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Sample records for ataxia-telangiectasia cells exposed

  1. Chromosome aberrations in ataxia telangiectasia cells exposed to heavy ions

    Science.gov (United States)

    Kawata, T.; Cucinotta, F.; George, K.; Wu, H.; Shigematsu, N.; Furusawa, Y.; Uno, T.; Isobe, K.; Ito, H.

    Understanding of biological effects of heavy ions is important to assess healt h risk in space. One of the most important issues may be to take into account individual susceptibility. Ataxia telangiectasia (A-T) cells are known to exhibit abnormal responses to radiations but the mechanism of hyper radiosensitivity of A-T still remains unknown. We report chromosome aberrations in normal human fibroblasts and AT fibroblasts exposed to low- and high-LET radiations. A chemical-induced premature chromosome condensation (PCC) technique combined with chromosome- painting technique was applied to score chromosome aberrations in G2/M-phase cells. Following gamma irradiation, GM02052 cells were approximately 5 times more sensitive to g-rays than AG1522 cells. GM02052 cells had a much higher frequency of deletions and misrejoining than AG1522 cells. When the frequency of complex type aberrations was compared, GM02052 cells showed more than 10 times higher frequency than AG1522 cells. The results will be compared with those obtained from high-LET irradiations.

  2. Abnormal regulation of DNA replication and increased lethality in ataxia telangiectasia cells exposed to carcinogenic agents

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    Jaspers, N.G.; de Wit, J.; Regulski, M.R.; Bootsma, D.

    1982-01-01

    The effect of different carcinogenic agents on the rate of semiconservative DNA replication in normal and ataxia telangiectasis (AT) cells was investigated. The rate of DNA synthesis in all AT cell strains tested was depressed to a significantly lesser extent than in normal cells after exposure to X-rays under oxia or hypoxia or to bleomycin, agents to which AT cells are hypersensitive. In contrast, inhibition of DNA replication in normal human and AT cells was similar after treatment with some DNA-methylating agents or mitomycin C. Colony-forming ability of AT cells treated with these agents was not different from normal cells. Treatment with 4-nitroquinoline 1-oxide elicited a variable response in both AT and normal cell strains. In some strains, including those shown to be hypersensitive to the drug by other workers, the inhibition of DNA synthesis was more pronounced than in other cell strains, but no significant difference between AT and normal cells could be detected. The rejoining of DNA strand breaks induced by X-rays, measured by DNA elution techniques, occurred within l2 hr after treatment and could not be correlated with the difference in DNA synthesis inhibition in AT and normal cells. After low doses of X-rays, AT cells rejoined single-strand breaks slightly more slowly than did normal cells. The rate of DNA replication in X-irradiation AT and normal cells was not affected by nicotinamide, an inhibitor of poly(adenosine diphosphate ribose) synthesis. These data indicate that the diminished inhibition of DNA replication in carcinogen-treated AT cells (a) is a general characteristic of all AT cell strains, (b) correlates with AT cellular hypersensitivity, (c) is not directly caused by the bulk of the DNA strand breaks produced by carcinogenic agents, and (d) is not based on differences in the induction of poly(adenosine diphosphate ribose) synthesis between X-irradiated AT and normal cells.

  3. Ataxia - telangiectasia

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001394.htm Ataxia - telangiectasia To use the sharing features on this page, please enable JavaScript. Ataxia-telangiectasia is a rare childhood disease. It affects ...

  4. Ataxia Telangiectasia

    Science.gov (United States)

    Ataxia-telangiectasia (A-T) is a rare, inherited disease. It affects the nervous system, immune system, and ... young children, usually before age 5. They include Ataxia - trouble coordinating movements Poor balance Slurred speech Tiny, ...

  5. Targeted disruption of Ataxia-telangiectasia mutated gene in miniature pigs by somatic cell nuclear transfer

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    Kim, Young June; Ahn, Kwang Sung; Kim, Minjeong; Kim, Min Ju; Park, Sang-Min; Ryu, Junghyun; Ahn, Jin Seop; Heo, Soon Young; Kang, Jee Hyun; Choi, You Jung [Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan (Korea, Republic of); Choi, Seong-Jun [Institute of Tissue Regeneration Engineering, Dankook University, Cheonan (Korea, Republic of); Shim, Hosup, E-mail: shim@dku.edu [Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan (Korea, Republic of); Institute of Tissue Regeneration Engineering, Dankook University, Cheonan (Korea, Republic of); Department of Physiology, Dankook University School of Medicine, Cheonan (Korea, Republic of)

    2014-10-03

    Highlights: • ATM gene-targeted pigs were produced by somatic cell nuclear transfer. • A novel large animal model for ataxia telangiectasia was developed. • The new model may provide an alternative to the mouse model. - Abstract: Ataxia telangiectasia (A-T) is a recessive autosomal disorder associated with pleiotropic phenotypes, including progressive cerebellar degeneration, gonad atrophy, and growth retardation. Even though A-T is known to be caused by the mutations in the Ataxia telangiectasia mutated (ATM) gene, the correlation between abnormal cellular physiology caused by ATM mutations and the multiple symptoms of A-T disease has not been clearly determined. None of the existing ATM mouse models properly reflects the extent to which neurological degeneration occurs in human. In an attempt to provide a large animal model for A-T, we produced gene-targeted pigs with mutations in the ATM gene by somatic cell nuclear transfer. The disrupted allele in the ATM gene of cloned piglets was confirmed via PCR and Southern blot analysis. The ATM gene-targeted pigs generated in the present study may provide an alternative to the current mouse model for the study of mechanisms underlying A-T disorder and for the development of new therapies.

  6. Analysis of Residual DSBs in Ataxia-Telangiectasia Lymphoblast Cells Initiating Apoptosis

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    Teresa Anglada

    2016-01-01

    Full Text Available In order to examine the relationship between accumulation of residual DNA double-strand breaks (DSBs and cell death, we have used a control and an ATM (Ataxia-Telangiectasia Mutated defective cell line, as Ataxia-Telangiectasia (AT cells tend to accumulate residual DSBs at long times after damage infliction. After irradiation, AT cells showed checkpoint impairment and a fraction of cells displayed an abnormal centrosome number and tetraploid DNA content, and this fraction increased along with apoptosis rates. At all times analyzed, AT cells displayed a significantly higher rate of radiation-induced apoptosis than normal cells. Besides apoptosis, 70–85% of the AT viable cells (TUNEL-negative carried ≥10 γH2AX foci/cell, while only 12–27% of normal cells did. The fraction of AT and normal cells undergoing early and late apoptosis were isolated by flow cytometry and residual DSBs were concretely scored in these populations. Half of the γH2AX-positive AT cells undergoing early apoptosis carried ≥10 γH2AX foci/cell and this fraction increased to 75% in late apoptosis. The results suggest that retention of DNA damage-induced γH2AX foci is an indicative of lethal DNA damage, as cells undergoing apoptosis are those accumulating more DSBs. Scoring of residual γH2AX foci might function as a predictive tool to assess radiation-induced apoptosis.

  7. Stable radioresistance in ataxia-telangiectasia cells containing DNA from normal human cells

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    Kapp, L.N.; Painter, R.B. (California Univ., San Francisco, CA (USA). Lab. of Radiobiology)

    1989-11-01

    SV40-transformed ataxia-telangiectasia (AT) cells were transfected with a cosmid containing a normal human DNA library and selectable marker, the neo gene, which endows successfully transformed mammalian cells with resistance to the antibiotic G418. Cells from this line were irradiated with 50 Gy of X-rays and fused with non-transfected AT cells. Among the G418-resistant colonies recovered was one stably resistant to radiation. Resistance to ionizing radiation of both primary transfectant line and its fusion derivative was intermediate between that of AT cells and normal cells, as assayed by colony-forming ability and measurement of radiation-induced G{sub 2} chromatic aberrations; both cell lines retained AT-like radioresistant DNA synthesis. Results suggest that, because radioresistance in transfected cells was not as great as in normal human cells, two hallmarks of AT, radiosensitivity and radioresistant DNA synthesis, may still be the result of a single defective AT gene. (author).

  8. Targeted disruption of Ataxia-telangiectasia mutated gene in miniature pigs by somatic cell nuclear transfer.

    Science.gov (United States)

    Kim, Young June; Ahn, Kwang Sung; Kim, Minjeong; Kim, Min Ju; Park, Sang-Min; Ryu, Junghyun; Ahn, Jin Seop; Heo, Soon Young; Kang, Jee Hyun; Choi, You Jung; Choi, Seong-Jun; Shim, Hosup

    2014-10-03

    Ataxia telangiectasia (A-T) is a recessive autosomal disorder associated with pleiotropic phenotypes, including progressive cerebellar degeneration, gonad atrophy, and growth retardation. Even though A-T is known to be caused by the mutations in the Ataxia telangiectasia mutated (ATM) gene, the correlation between abnormal cellular physiology caused by ATM mutations and the multiple symptoms of A-T disease has not been clearly determined. None of the existing ATM mouse models properly reflects the extent to which neurological degeneration occurs in human. In an attempt to provide a large animal model for A-T, we produced gene-targeted pigs with mutations in the ATM gene by somatic cell nuclear transfer. The disrupted allele in the ATM gene of cloned piglets was confirmed via PCR and Southern blot analysis. The ATM gene-targeted pigs generated in the present study may provide an alternative to the current mouse model for the study of mechanisms underlying A-T disorder and for the development of new therapies.

  9. Cell and Molecular Biology of Ataxia Telangiectasia Heterozygous Human Mammary Epithelial Cells Irradiated in Culture

    Science.gov (United States)

    Richmond, Robert C.

    2001-01-01

    Autologous isolates of cell types from obligate heterozygotes with the autosomal disorder ataxia-telangiectasia (A-T)were used to begin a tissue culture model for assessing pathways of radiation-induced cancer formation in this target tissue. This was done by establishing cultures of stromal fibroblasts and long-term growth human mammary epithelial cells (HMEC) in standard 2-dimensional tissue culture in order to establish expression of markers detailing early steps of carcinogenesis. The presumptive breast cancer susceptibility of A-T heterozygotes as a sequel to damage caused by ionizing radiation provided reason to study expression of markers in irradiated HMEC. Findings from our study with HMEC have included determination of differences in specific protein expression amongst growth phase (e.g., log vs stationary) and growth progression (e.g., pass 7 vs pass 9), as well as differences in morphologic markers within populations of irradiated HMEC (e.g., development of multinucleated cells).

  10. Small-molecule inhibitors of Ataxia Telangiectasia and Rad3 related kinase (ATR) sensitize lymphoma cells to UVA radiation

    DEFF Research Database (Denmark)

    Biskup, Edyta; Naym, David Gram; Gniadecki, Robert

    2016-01-01

    and require more aggressive therapies. OBJECTIVE: The aim of this project was to investigate whether inhibition of Ataxia Telangiectasia and Rad3 related kinase (ATR) may enhance efficacy of phototherapy. METHODS: CTCL cell lines (MyLa2000, SeAx and Mac2a) served as in vitro cell models. ATR and Chk1 were...

  11. Ataxia-telangiectasia mutated (ATM) deficiency decreases reprogramming efficiency and leads to genomic instability in iPS cells.

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    Kinoshita, Taisuke; Nagamatsu, Go; Kosaka, Takeo; Takubo, Keiyo; Hotta, Akitsu; Ellis, James; Suda, Toshio

    2011-04-08

    During cell division, one of the major features of somatic cell reprogramming by defined factors, cells are potentially exposed to DNA damage. Inactivation of the tumor suppressor gene p53 raised reprogramming efficiency but resulted in an increased number of abnormal chromosomes in established iPS cells. Ataxia-telangiectasia mutated (ATM), which is critical in the cellular response to DNA double-strand breaks, may also play an important role during reprogramming. To clarify the function of ATM in somatic cell reprogramming, we investigated reprogramming in ATM-deficient (ATM-KO) tail-tip fibroblasts (TTFs). Although reprogramming efficiency was greatly reduced in ATM-KO TTFs, ATM-KO iPS cells were successfully generated and showed the same proliferation activity as WT iPS cells. ATM-KO iPS cells had a gene expression profile similar to ES cells and WT iPS cells, and had the capacity to differentiate into all three germ layers. On the other hand, ATM-KO iPS cells accumulated abnormal genome structures upon continuous passages. Even with the abnormal karyotype, ATM-KO iPS cells retained pluripotent cell characteristics for at least 20 passages. These data indicate that ATM does participate in the reprogramming process, although its role is not essential.

  12. Donor-derived brain tumor following neural stem cell transplantation in an ataxia telangiectasia patient.

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    Ninette Amariglio

    2009-02-01

    Full Text Available BACKGROUND: Neural stem cells are currently being investigated as potential therapies for neurodegenerative diseases, stroke, and trauma. However, concerns have been raised over the safety of this experimental therapeutic approach, including, for example, whether there is the potential for tumors to develop from transplanted stem cells. METHODS AND FINDINGS: A boy with ataxia telangiectasia (AT was treated with intracerebellar and intrathecal injection of human fetal neural stem cells. Four years after the first treatment he was diagnosed with a multifocal brain tumor. The biopsied tumor was diagnosed as a glioneuronal neoplasm. We compared the tumor cells and the patient's peripheral blood cells by fluorescent in situ hybridization using X and Y chromosome probes, by PCR for the amelogenin gene X- and Y-specific alleles, by MassArray for the ATM patient specific mutation and for several SNPs, by PCR for polymorphic microsatellites, and by human leukocyte antigen (HLA typing. Molecular and cytogenetic studies showed that the tumor was of nonhost origin suggesting it was derived from the transplanted neural stem cells. Microsatellite and HLA analysis demonstrated that the tumor is derived from at least two donors. CONCLUSIONS: This is the first report of a human brain tumor complicating neural stem cell therapy. The findings here suggest that neuronal stem/progenitor cells may be involved in gliomagenesis and provide the first example of a donor-derived brain tumor. Further work is urgently needed to assess the safety of these therapies.

  13. Identification of 4 ataxia telangiectasia cell lines hypersensitive to. gamma. -irradiation but not to hydrogen peroxide

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    Cantoni, O.; Sestili, P.; Santoro, M.P.; Tannoia, M.C.; Cattabeni, F. (Universita degli Studi di Urbino (Italy). Istituto di Farmacologia e Farmacognosia and Centro di Farmacologia Oncologia Sperimentale); Novelli, G.; Dallapiccola, B. (Universit degli Studi di Urbino (Italy). Cattedra di Genetica); Fiorilli, M. (Universita di Roma ' La Sapienze' (Italy). Cattedra di Allergologia e Immunologia Clinica)

    1989-09-01

    The effct of hydrogen peroxide on the rate of semi-conservative DNA synthesis in ataxia telangiectasia (AT) and normal human lymphoblastoid cells was investigated. The rate of DNA synthesis in AT cells was not depressed to a lesser extent than in normal cells, as might have been expected since H{sub 2O2} is a radiomimetic agent. On the contrary, 4 AT cell lines displayed a higher sensitivity to the inhibitory effect of H{sub 2O2} on DNA synthesis than 2 normal cell lines. Comparable levels of cytotoxicity were detected in cell vaibility studies. Furthermore, neither the level of DNA breakage produced by H{sub 2O2}, nor the rate of repair of these lesions was signigicantly different in normal and AT cells. Together, these results indicate that the AT cell lines utilized in this study are not hypersensitive to the oxidant. It is suggested that H-2-O-2 may not induce lethality via the direct ation of the hydroxyl radical (OH). (Author). 20 refs.; 3 figs.; 1 tab.

  14. Impaired recovery and mutagenic SOS-like responses in ataxia telangiectasia cells

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    Hilgers, G. (Universite Libre de Bruxelles (Belgium) Rijksuniversiteit Leiden (Netherlands)); Abrahams, P.J. (Rijksuniversiteit Leiden (Netherlands)); Chen, Y.Q. (Universite Libre de Bruxelles (Belgium)); Schouten, R. (Rijksuniversiteit Leiden (Netherlands)); Cornelis, J.J. (Universite Libre de Bruxelles (Belgium) Institut Pasteur, 75 - Paris (France)); Lowe, J.E. (Sussex Univ., Brighton (UK)); Eb, A.J. van der (Rijksuniversiteit Leiden (Netherlands)); Rommelaere, J. (Universite Libre de Bruxelles (Belgium) Institut Pasteur, 75 - Paris (France))

    1989-01-01

    Radiosensitive fibroblasts from patients with ataxia telangiectasia (AT) were studied for their proficiency in two putative eukaryotic SOS-like responses, namely the enhanced reactivation (ER) and enhanced mutagenesis of damaged viruses infecting pre-irradiated versus mock-treated cells. A previous report indicated that, unlike normal human cells, a line of AT fibroblasts (AT5BIVA) could not be induced to express ER of damaged parvovirus H-1, a single-stranded DNA virus, by UV- or X-irradiation. In the present study, AT5BIVA fibroblasts were also distinguished from normal cells by the inability of the former to achieve enhanced mutagenesis of damaged H-1 virus upon cell UV-irradiation. In contrast, dose-response and time-course experiments revealed normal levels of ER of Herpes simplex virus 1, a double-stranded DNA virus, in X- or UV-irradiated AT5BIVA cells. Taken together, these data point to a possible deficiency of AT cells in a conditioned mutagenic process that contributes to a greater extent to the recovery of damaged single-stranded than double-stranded DNA. Such a defect may concern the replication of damaged DNA or the generation of signals promoting the latter process and may be related to the lack of radiation-induced delay that is typical of AT cell DNA synthesis. (author).

  15. Ataxia-telangiectasia mutated (ATM) deficiency decreases reprogramming efficiency and leads to genomic instability in iPS cells

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    Kinoshita, Taisuke [Department of Cell Differentiation, The Sakaguchi Laboratory, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Nagamatsu, Go, E-mail: gonag@sc.itc.keio.ac.jp [Department of Cell Differentiation, The Sakaguchi Laboratory, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Kosaka, Takeo [Department of Urology, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Takubo, Keiyo [Department of Cell Differentiation, The Sakaguchi Laboratory, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Hotta, Akitsu [Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Department of Reprogramming Science, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto (Japan); Ellis, James [Ontario Human iPS Cell Facility, Molecular Genetics, University of Toronto, Developmental and Stem Cell Biology, SickKids, Toronto, Canada MG1L7 (Canada); Suda, Toshio, E-mail: sudato@sc.itc.keio.ac.jp [Department of Cell Differentiation, The Sakaguchi Laboratory, School of Medicine, Keio University, Tokyo 160-8582 (Japan)

    2011-04-08

    Highlights: {yields} iPS cells were induced with a fluorescence monitoring system. {yields} ATM-deficient tail-tip fibroblasts exhibited quite a low reprogramming efficiency. {yields} iPS cells obtained from ATM-deficient cells had pluripotent cell characteristics. {yields} ATM-deficient iPS cells had abnormal chromosomes, which were accumulated in culture. -- Abstract: During cell division, one of the major features of somatic cell reprogramming by defined factors, cells are potentially exposed to DNA damage. Inactivation of the tumor suppressor gene p53 raised reprogramming efficiency but resulted in an increased number of abnormal chromosomes in established iPS cells. Ataxia-telangiectasia mutated (ATM), which is critical in the cellular response to DNA double-strand breaks, may also play an important role during reprogramming. To clarify the function of ATM in somatic cell reprogramming, we investigated reprogramming in ATM-deficient (ATM-KO) tail-tip fibroblasts (TTFs). Although reprogramming efficiency was greatly reduced in ATM-KO TTFs, ATM-KO iPS cells were successfully generated and showed the same proliferation activity as WT iPS cells. ATM-KO iPS cells had a gene expression profile similar to ES cells and WT iPS cells, and had the capacity to differentiate into all three germ layers. On the other hand, ATM-KO iPS cells accumulated abnormal genome structures upon continuous passages. Even with the abnormal karyotype, ATM-KO iPS cells retained pluripotent cell characteristics for at least 20 passages. These data indicate that ATM does participate in the reprogramming process, although its role is not essential.

  16. Radiation Dose-effects on Cell Cycle, Apoptosis, and Marker Expression of Ataxia Telangiectasia-Heterozygous Human Breast Epithelial Cells

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    Cruz, A.; Bors, K.; Jansen, H.; Richmond, R.

    2003-01-01

    Ataxia-telangiectasia (A-T) is a radiation-sensitive genetic condition. AT-heterozygous human mammary epithelial cells (HMEC) were irradiated using a Cs137 source in order to compare cell cycle, apoptosis, and marker expression responses across 3 radiation doses. No differences in cell cycle and apoptosis were found with any of the radiation doses used (30, 60, and 90 rads) compared with the unirradiated control (0 rad). At the same doses, however, differences were found in marker expression, such as keratin 18 (kl8), keratin 14 (k14), insulin-like growth factor I receptor (IGF-IR), and connexin 43 (cx43). This may indicate that radiation sensitivity in the heterozygous state may be initiated through signal transduction responses.

  17. Caffeine Suppresses Apoptosis of Bladder Cancer RT4 Cells in Response to Ionizing Radiation by Inhibiting Ataxia Telangiectasia Mutated-Chk2-p53 Axis

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    Zhe-Wei Zhang; Jing Xiao; Wei Luo; Bo-Han Wang; Ji-Min Chen

    2015-01-01

    Background:Caffeine suppresses ataxia telangiectasia and Rad3 related and ataxia telangiectasia mutated (ATM) activities;ATM is the major kinase for DNA damage detection.This study aimed to investigate the effects of caffeine on DNA damage responses in cells from the bladder cancer cell line RT4 those were exposed to ionizing radiation (IR).Methods:Immunofluorescent staining was performed to investigate changes in the proteins involved in DNA damage responses with or without caffeine.A mouse xenograft model was used to study the effects of caffeine on the DNA damage responses.Western blotting was used to investigate the effects of caffeine pretreatment on the ATM-Chk2-p53-Puma axis,while real-time polymerase chain reaction (RT-PCR) assessed changes in messenger RNA levels of p53 and downstream targets responding to IR.Finally,terminal deoxynucleotidyl transferase-dUTP nick end labeling assay.Western blotting and colony formation assay were used to measure the effects of caffeine on radiation-related apoptosis.All of the data were analyzed with a two-tailed Student's t-test.Results:Immunofluorescent staining showed that caffeine pretreatment profoundly suppressed the formation ofγH2AXand p53-binding protein 1 foci in RT4 cells in response to irradiation.Cellular and animal experiments suggested that this suppression was mediated by suppression of the ATM-Chk2-p53-Puma DNA damage-signaling axis.RT-PCR indicated caffeine also attenuated transactivation of p53 and p53-inducible genes.The colony formation assay revealed that caffeine displayed radioprotective effects on RT4 cells in response to low-dose radiation compared to the radiosensitization effects on T24 cells.Conclusion:Caffeine may inhibit IR-related apoptosis of bladder cancer RT4 cells by suppressing activation of the ATM-Chk2-p53-Puma axis.

  18. Caffeine Suppresses Apoptosis of Bladder Cancer RT4 Cells in Response to Ionizing Radiation by Inhibiting Ataxia Telangiectasia Mutated-Chk2-p53 Axis

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    Zhe-Wei Zhang

    2015-01-01

    Full Text Available Background: Caffeine suppresses ataxia telangiectasia and Rad3 related and ataxia telangiectasia mutated (ATM activities; ATM is the major kinase for DNA damage detection. This study aimed to investigate the effects of caffeine on DNA damage responses in cells from the bladder cancer cell line RT4 those were exposed to ionizing radiation (IR. Methods: Immunofluorescent staining was performed to investigate changes in the proteins involved in DNA damage responses with or without caffeine. A mouse xenograft model was used to study the effects of caffeine on the DNA damage responses. Western blotting was used to investigate the effects of caffeine pretreatment on the ATM-Chk2-p53-Puma axis, while real-time polymerase chain reaction (RT-PCR assessed changes in messenger RNA levels of p53 and downstream targets responding to IR. Finally, terminal deoxynucleotidyl transferase-dUTP nick end labeling assay. Western blotting and colony formation assay were used to measure the effects of caffeine on radiation-related apoptosis. All of the data were analyzed with a two-tailed Student′s t-test. Results: Immunofluorescent staining showed that caffeine pretreatment profoundly suppressed the formation of γH2AXand p53-binding protein 1 foci in RT4 cells in response to irradiation. Cellular and animal experiments suggested that this suppression was mediated by suppression of the ATM-Chk2-p53-Puma DNA damage-signaling axis. RT-PCR indicated caffeine also attenuated transactivation of p53 and p53-inducible genes. The colony formation assay revealed that caffeine displayed radioprotective effects on RT4 cells in response to low-dose radiation compared to the radiosensitization effects on T24 cells. Conclusion: Caffeine may inhibit IR-related apoptosis of bladder cancer RT4 cells by suppressing activation of the ATM-Chk2-p53-Puma axis.

  19. Genetics Home Reference: ataxia-telangiectasia

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    ... Me Understand Genetics Home Health Conditions ataxia-telangiectasia ataxia-telangiectasia Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Ataxia-telangiectasia is a rare inherited disorder that affects ...

  20. Defective signaling through the B cell antigen receptor in Epstein-Barr virus-transformed ataxia-telangiectasia cells.

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    Khanna, K K; Yan, J; Watters, D; Hobson, K; Beamish, H; Spring, K; Shiloh, Y; Gatti, R A; Lavin, M F

    1997-04-04

    A characteristic series of immunological abnormalities are observed in the human genetic disorder ataxia-telangiectasia (A-T). The recent cloning of a gene mutated in this syndrome provides additional evidence for a defect in intracellular signaling in A-T. We have investigated the possibility that signaling through the B cell antigen receptor is one manifestation of the A-T defect. In response to cross-linking of the B cell receptor, several A-T cell lines were defective in their mitogenic response; in addition Ca2+ mobilization from internal stores was either absent or considerably reduced in these cell lines in response to cross-linking. The defect in signaling was not due to difference in expression of surface immunoglobulin. The defective response in A-T cells was also evident in several arms of the intracellular cascade activated by B cell cross-linking. Tyrosine phosphorylation of phospholipase Cgamma1, a key step in activation of the enzyme, was reduced or negligible in some A-T cell lines. This defect in signaling was also seen at the level of Lyn tyrosine kinase activation and its association with and activation of phosphatidylinositol 3-kinase. Our results provide evidence for a role for the ATM gene product in intracellular signaling which may account at least in part for the abnormalities in B cell function in A-T.

  1. Ataxia-telangiectasia

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    Nelson Pires Ferreira

    1966-09-01

    Full Text Available São apresentados os casos de dois irmãos com ataxia-telangiectasia, estudados sob os pontos de vista clínico, eletrencefalográfico, liquórico e encefalográfico. O autor resume os achados de diversos autores e chama a atenção para a regressão parcial da síndrome cerebelar em ambos os pacientes, fato ainda não referido na literatura.

  2. Abnormal levels of UV-induced unscheduled DNA synthesis in ataxia telangiectasia cells after exposure to ionizing radiation

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    Jaspers, N.G.J. (Erasmus Universiteit, Rotterdam (Netherlands). Dept. of Cell Biology and Genetics; Nederlandse Centrale Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek, Rijswijk. Medical Biological Lab.); Bootsma, D. (Erasmus Universiteit, Rotterdam (Netherlands). Dept. of Cell Biology and Genetics)

    1982-01-01

    In cultured cells from normal individuals and from patients having ataxia telangiectasia (AT) the rate of unscheduled DNA synthesis (UDS) induced by UV light was investigated by autoradiography. The number of grains in 6 different AT cell strains was similar to that observed in normal cells. Exposure of normal cells to doses of X-rays up to 20 krad had no influence on the rate of UV-induced UDS. In contrast, the UV-induced UDS was significantly modified in AT cells by treatment with X-rays. In AT cell strains that were reported to have reduced levels of ..gamma..-ray-induced repair DNA synthesis ('excision-deficient' AT cells) the effect of X-rays on UV-induced UDS was inhibitory, whereas UV-induced UDS was stimulated by X-ray exposure in 'excision-proficient' AT cell strains. Different UV and X-ray dose-response relationships were seen in the two categories of AT cell strains.

  3. Cell death, chromosome damage and mitotic delay in normal human, ataxia telangiectasia and retinoblastoma fibroblasts after x-irradiation.

    Science.gov (United States)

    Zampetti-Bosseler, F; Scott, D

    1981-05-01

    We recently showed (Scott and Zampetti-Bosseler 1980) that X-ray sensitive mouse lymphoma cells sustain more chromosome damage, mitotic delay and spindle defects than X-ray resistant cells. We proposed that (a) chromosome aberrations contribute much more to lethality than spindle defects, and (b) that DNA lesions are less effectively repaired in the sensitive cells and give rise to more G2 mitotic delay and chromosome aberrations. Our present results on human fibroblasts with reported differential sensitivity to ionizing radiation (i.e. normal donors and patients with ataxia telangiectasia and retinoblastoma) support the first hypothesis since we observed a positive correlation between chromosome aberration frequencies and cell killing and no induced spindle defects. Our second hypothesis is however not substantiated since X-ray sensitive fibroblasts from the ataxia patient suffered less mitotic delay than cells from normal donors. A common lesion for mitotic delay and chromosome aberrations can still be assumed by adopting the hypothesis of Painter and Young (1981) that the defect in ataxia cells is not in repair but in a failure of DNA damage to initiate mitotic delay. In contrast to other reports, we found the retinoblastoma cells to be of normal radiation sensitivity (cell killing and aberration).

  4. What Is Ataxia-Telangiectasia?

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    ... About A-T Research Fundraising About Us About Ataxia-telangiectasia About A-T » WHAT IS A- ... develop slurred or distorted speech, and swallowing problems. Ataxia... The onset of this ataxia marks the beginning ...

  5. Hashimoto thyroiditis associated with ataxia telangiectasia.

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    Patiroglu, Turkan; Gungor, Hatice Eke; Unal, Ekrem; Kurtoglu, Selim; Yikilmaz, Ali; Patiroglu, Tahir

    2012-01-01

    Ataxia telangiectasia is a rare genetic disease characterized by neurological manifestations, infections, and cancers. In addition to these cardinal features, different autoimmune diseases can be seen in patients with ataxia telangiectasia. Although there were reports of positive autoimmune thyroid antibodies associated with ataxia telangiectasia, to our knowledge, we report the first cases of nodular Hashimoto thyroiditis in two patients with ataxia telangiectasia in the English medical literature. These cases illustrate that despite the rarity of nodular Hashimoto thyroiditis associated with ataxia telangiectasia, physicians should be aware of this possibility. Furthermore, thyroid examination of patient with ataxia telangiectasia is recommended for early diagnosis.

  6. Uterine tumors in ataxia-telangiectasia.

    Science.gov (United States)

    Gatti, R A; Nieberg, R; Boder, E

    1989-02-01

    Roughly one-third of patients with ataxia-telangiectasia (AT) develop malignant tumors, usually of lymphoid origin. AT patients also exhibit progeric changes. We describe three patients, between the ages of 27 and 32 years, with uterine tumors: one with a frank leiomyosarcoma and chronic T-cell leukemia, one with a multilobulated leiomyoma of uncertain malignant potential, and one with an unremarkable leiomyoma. Thus, the spectrum of tumors in AT patients beyond adolescence includes nonlymphoid malignancies and precocious, benign leiomyomas.

  7. High-LET Radiation Induced Chromosome Aberrations in Normal and Ataxia Telangiectasia Fibroblast Cells

    Science.gov (United States)

    Kawata, Tetsuya; George, Ms Kerry; Cucinotta, Francis A.; Shigematsu, Naoyuki; Ito, Hisao; Furusawa, Yoshiya; Uno, Takashi

    We investigated the effects of heavy ions beams on chromosomal aberrations in normal and AT cells. Normal and AT fibroblast cells arrested at G0/G1 phase were irradiated with 2 Gy of X-rays, 490 MeV/u Silicon (LET 55 keV/micron), 500 MeV/u Iron (LET 185 keV/micron) and 200 MeV/u Iron (LET 440 keV/micron) particles, and then cells were allowed to repair for 24 hours at 37 degrees before subculture. Calyculin-A induced PCC method was employed to collect G2/M chromosomes and whole DNA probes 1 and 3 were used to analyze chromosomal aberrations such as color-junctions, deletions, simple exchanges (incomplete and reciprocal exchanges) and complex-type exchanges. The percentages of aberrant cells were higher when normal and AT cells were exposed to heavy ions compared to X-rays, and had a tendency to increase with increasing LET up to 185 keV/micron and then decreased at 440 keV/micron. When the frequency of color-junctions per cell was compared after X-ray exposure, AT cells had around three times higher frequency of color-junctions (mis-rejoining) than normal cells. However, at 185 keV/micron there was no difference in the frequency of color-junctions between two cell lines. It was also found that the frequency of simple exchanges per cell was almost constant in AT cells regardless LET levels, but it was LET dependent for normal cells. Interestingly, the frequency of simple exchanges was higher for normal fibroblast cells when it was compared at 185 keV/micron, but AT cells had more complex-type exchanges at the same LET levels. Heavy ions are more efficient in inducing chromosome aberrations in normal and AT cells compared to X-rays, and the aberration types between normal and AT fibroblast appeared different probably due to difference in the ATM gene function.

  8. Ataxia-telangiectasia group D complementing gene (ATDC promotes lung cancer cell proliferation by activating NF-κB pathway.

    Directory of Open Access Journals (Sweden)

    Zhong-Ping Tang

    Full Text Available Previous studies suggested Ataxia-telangiectasia group D complementing gene (ATDC as an oncogene in many types of cancer. However, its expression and biological functions in non-small cell lung cancer (NSCLC remain unclear. Herein, we investigated its expression pattern in 109 cases of human NSCLC samples by immunohistochemistry and found that ATDC was overexpressed in 62 of 109 NSCLC samples (56.88%. ATDC overexpression correlated with histological type (p<0.0001, tumor status (p = 0.0227 and histological differentiation (p = 0.0002. Next, we overexpressed ATDC in normal human bronchial epithelial cell line HBE and depleted its expression in NSCLC cell lines A549 and H1299. MTT and colony formation assay showed that ATDC overexpression promoted cell proliferation while its depletion inhibited cell growth. Furthermore, cell cycle analysis showed that ATDC overexpression decreased the percentage of cells in G1 phase and increased the percentage of cells in S phase, while ATDC siRNA treatment increased the G1 phase percentage and decreased the S phase percentage. Further study revealed that ATDC overexpression could up-regulate cyclin D1 and c-Myc expression in HBE cells while its depletion down-regulated cyclin D1 and c-Myc expression in A549 and H1299 cells. In addition, ATDC overexpression was also associated with an increased proliferation index, cyclin D1 and c-Myc expression in human NSCLC samples. Further experiments demonstrated that ATDC up-regulated cyclin D1 and c-Myc expression independent of wnt/β-catenin or p53 signaling pathway. Interestingly, ATDC overexpression increased NF-κB reporter luciferase activity and p-IκB protein level. Correspondingly, NF-κB inhibitor blocked the effect of ATDC on up-regulation of cyclin D1 and c-Myc. In conclusion, we demonstrated that ATDC could promote lung cancer proliferation through NF-κB induced up-regulation of cyclin D1 and c-Myc.

  9. Nitric oxide induces ataxia telangiectasia mutated (ATM) protein-dependent γH2AX protein formation in pancreatic β cells.

    Science.gov (United States)

    Oleson, Bryndon J; Broniowska, Katarzyna A; Schreiber, Katherine H; Tarakanova, Vera L; Corbett, John A

    2014-04-18

    In this study, the effects of cytokines on the activation of the DNA double strand break repair factors histone H2AX (H2AX) and ataxia telangiectasia mutated (ATM) were examined in pancreatic β cells. We show that cytokines stimulate H2AX phosphorylation (γH2AX formation) in rat islets and insulinoma cells in a nitric oxide- and ATM-dependent manner. In contrast to the well documented role of ATM in DNA repair, ATM does not appear to participate in the repair of nitric oxide-induced DNA damage. Instead, nitric oxide-induced γH2AX formation correlates temporally with the onset of irreversible DNA damage and the induction of apoptosis. Furthermore, inhibition of ATM attenuates cytokine-induced caspase activation. These findings show that the formation of DNA double strand breaks correlates with ATM activation, irreversible DNA damage, and ATM-dependent induction of apoptosis in cytokine-treated β cells.

  10. The response of normal and ataxia-telangiectasia cells to bleomycin: relationships between chromosome damage, cell cycle delay and cell killing.

    Science.gov (United States)

    Zampetti-Bosseler, F; Scott, D

    1985-08-01

    In agreement with our earlier observation (Scott and Zampetti-Bosseler, 1982) on X-irradiated normal and ataxia-telangiectasia (A-T) fibroblasts, we now report that after bleomycin or neocarzinostatin treatment also, A-T cells exhibit less G2 delay than normal cells. We confirm that A-T cells sustain more chromosome damage and lethality than normal cells after bleomycin. These observations support the hypothesis (Painter and Young, 1980) that A-T cells are defective in the recognition of certain lesions which normally lead to delays in progression through the cell cycle, during which they are repaired, and which, if unrepaired, lead to cell-lethal chromosome damage. However, we find that after bleomycin, as opposed to X-rays, the contribution of this type of lesion to cell death is minimal. The predominant lesions leading to cell death after bleomycin are not manifested at chromosome aberrations and do not lead to G2 delay or DNA-synthesis inhibition. A-T cells are defective in the recognition and/or repair of both types of lesion.

  11. Ataxia-Telangiectasia (A-T)

    Science.gov (United States)

    Ataxia-Telangiectasia (A-T) What is ataxia-telangiectasia (A-T)? A-T is a hereditary progressive neurodegenerative disorder that begins in early childhood. ... nervous system. What are the symptoms of A-T? An affected child usually begins to show signs ...

  12. Complementation analysis of ataxia-telangiectasia

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, N.G.; Painter, R.B.; Paterson, M.C.; Kidson, C.; Inoue, T.

    1985-01-01

    In a number of laboratories genetic analysis of ataxia-telangiectasia (AT) has been performed by studying the expression of the AT phenotype in fused somatic cells or mixtures of cell-free extracts from different patients. Complementation of the defective response to ionizing radiation was observed frequently, considering four different parameters for radiosensitivity in AT. The combined results from studies on cultured fibroblasts or lymphoblastoid cells from 17 unrelated families revealed the presence of at least four and possibly nine complementation groups. These findings suggest that there is an extensive genetic heterogeneity in AT. More extensive studies are needed for an integration of these data and to provide a set of genetically characterized cell strains for future research of the AT genetic defect.

  13. Deficient expression of enhanced reactivation of parvovirus H-1 in ataxia telangiectasia cells irradiated with X-rays or u. v. light

    Energy Technology Data Exchange (ETDEWEB)

    Hilgers, G.; Chen, Y.Q.; Cornelis, J.J.; Rommelaere, J.

    1987-02-01

    Cells of patients with ataxia telangiectasia (AT), an inherited disease characterized by a high propensity to cancer, are hypersensitive to ionizing radiation. We investigated whether the hyper-radiosensitivity of AT cells correlated with a defect in their constitutive and/or conditional ability to rescue a damaged exogenous virus. For that purpose, parvovirus H-1, a single-stranded DNA virus whose intranuclear replication mostly relies on host cell functions, was used as a probe. The survival of u.v.- or gamma-irradiated H-1 was measured in X-, u.v.- or mock-irradiated human cells of normal (NB-E) or AT (AT5BIVA) origin. gamma-Irradiated H-1 survived to similar extents in untreated normal and AT cell lines. Both X- and u.v.-irradiation induced normal cells to achieve an enhanced reactivation (ER) of gamma- or u.v.-damaged H-1. In contrast, neither dose-effect curves nor time course revealed significant levels of ER expression after X- or u.v.-irradiation in AT5BIVA cells. Our results suggest that the impairment of ER of damaged parvoviruses may constitute a marker of the AT cell phenotype and be related to the radiosensitivity of AT cells.

  14. Ataxia Telangiectasia Mutated and Rad3 Related (ATR) Protein Kinase Inhibition Is Synthetically Lethal in XRCC1 Deficient Ovarian Cancer Cells

    Science.gov (United States)

    Sultana, Rebeka; Abdel-Fatah, Tarek; Perry, Christina; Moseley, Paul; Albarakti, Nada; Mohan, Vivek; Seedhouse, Claire; Chan, Stephen; Madhusudan, Srinivasan

    2013-01-01

    Introduction Ataxia telangiectasia mutated and Rad3 Related (ATR) protein kinase is a key sensor of single-stranded DNA associated with stalled replication forks and repair intermediates generated during DNA repair. XRCC1 is a critical enzyme in single strand break repair and base excision repair. XRCC1-LIG3 complex is also an important contributor to the ligation step of the nucleotide excision repair response. Methods In the current study, we investigated synthetic lethality in XRCC1 deficient and XRCC1 proficient Chinese Hamster ovary (CHO) and human ovarian cancer cells using ATR inhibitors (NU6027). In addition, we also investigated the ability of ATR inhibitors to potentiate cisplatin cytotoxicity in XRCC1 deficient and XRCC1 proficient CHO and human cancer cells. Clonogenic assays, alkaline COMET assays, γH2AX immunocytochemistry, FACS for cell cycle as well as FITC-annexin V flow cytometric analysis were performed. Results ATR inhibition is synthetically lethal in XRCC1 deficient cells as evidenced by increased cytotoxicity, accumulation of double strand DNA breaks, G2/M cell cycle arrest and increased apoptosis. Compared to cisplatin alone, combination of cisplatin and ATR inhibitor results in enhanced cytotoxicity in XRCC1 deficient cells compared to XRCC1 proficient cells. Conclusions Our data provides evidence that ATR inhibition is suitable for synthetic lethality application and cisplatin chemopotentiation in XRCC1 deficient ovarian cancer cells. PMID:23451157

  15. Ataxia telangiectasia mutated and Rad3 related (ATR protein kinase inhibition is synthetically lethal in XRCC1 deficient ovarian cancer cells.

    Directory of Open Access Journals (Sweden)

    Rebeka Sultana

    Full Text Available INTRODUCTION: Ataxia telangiectasia mutated and Rad3 Related (ATR protein kinase is a key sensor of single-stranded DNA associated with stalled replication forks and repair intermediates generated during DNA repair. XRCC1 is a critical enzyme in single strand break repair and base excision repair. XRCC1-LIG3 complex is also an important contributor to the ligation step of the nucleotide excision repair response. METHODS: In the current study, we investigated synthetic lethality in XRCC1 deficient and XRCC1 proficient Chinese Hamster ovary (CHO and human ovarian cancer cells using ATR inhibitors (NU6027. In addition, we also investigated the ability of ATR inhibitors to potentiate cisplatin cytotoxicity in XRCC1 deficient and XRCC1 proficient CHO and human cancer cells. Clonogenic assays, alkaline COMET assays, γH2AX immunocytochemistry, FACS for cell cycle as well as FITC-annexin V flow cytometric analysis were performed. RESULTS: ATR inhibition is synthetically lethal in XRCC1 deficient cells as evidenced by increased cytotoxicity, accumulation of double strand DNA breaks, G2/M cell cycle arrest and increased apoptosis. Compared to cisplatin alone, combination of cisplatin and ATR inhibitor results in enhanced cytotoxicity in XRCC1 deficient cells compared to XRCC1 proficient cells. CONCLUSIONS: Our data provides evidence that ATR inhibition is suitable for synthetic lethality application and cisplatin chemopotentiation in XRCC1 deficient ovarian cancer cells.

  16. G{sub 2}/M-phase arrest and release in ataxia telangiectasia and normal cells after exposure to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hong, J.H.; Gatti, R.A.; Huo, Y.K.; Chiang, C.S.; McBride, W.H. [Univ. of California School of Medicine, Los Angeles, CA (United States)

    1994-10-01

    Cells from patients with ataxia telangiectasia (AT) are abnormal in their response to irradiation as judged by clonogenic survival and accumulation in G{sub 2} phase. The relationship of the results of these two assays, however, is still a matter of controversy. Flow cytometry was used to measure the distribution of cells in the phases of the cell cycle after 2 Gy irradiation in Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs) and SV40-transformed fibroblasts. AT cells showed increased and prolonged accumulation in G{sub 2}/M phase regardless of the cell type (lymphoblastoid or fibroblast) or complementation group (A, C or D). To test the hypothesis that prolonged accumulation of AT cells in G{sub 2} phase after irradiation was not simply a reflection of their radiosensitivity, we gave iso-survival radiation doses to SV40-transformed fibroblasts of two AT and one control cell lines. The two AT cell lines exited from the G{sub 2}/M-phase block more slowly than control cells after each dose tested. This implies that prolonged accumulation in G{sub 2}/M phase in AT cells is not directly related to radiosensitivity as measured by clonogenic survival, but that factors involved in the exit from G{sub 2} phase after irradiation may be abnormally regulated. We found that G{sub 2}-phase arrest of AT cells did not necessarily result in a fatal consequence in the first cell cycle after irradiation. Furthermore, G{sub 2}-phase arrest did not lead to detectable DNA fragmentation characteristic of apoptosis as judged by gel electrophoresis. 37 refs., 6 figs.

  17. MicroRNA-223 Enhances Radiation Sensitivity of U87MG Cells In Vitro and In Vivo by Targeting Ataxia Telangiectasia Mutated

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Liping; Zhu, Ji [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Zaorsky, Nicholas G. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Deng, Yun [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Wu, Xingzhong [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai (China); Liu, Yong [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Liu, Fangqi; Cai, Guoxiang; Gu, Weilie [Department of Colorectal Cancer, Fudan University, Shanghai Cancer Center, Shanghai (China); Shen, Lijun [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Zhang, Zhen, E-mail: zhenzhang6@hotmail.com [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China)

    2014-03-15

    Purpose: Ataxia telangiectasia mutated (ATM) protein is important in the DNA damage response because it repairs radiation-induced damage in cancers. We examined the effect of microRNA-223 (miR-223), a regulator of ATM expression, on radiation sensitivity of cancer cells. Methods and Materials: Human embryonic kidney 293 T (293T) cells were infected with pLL3.7-miR-223 plasmid to generate the pLL3.7-miR-223 and -empty virus (EV) lentivirus (miR-223 and EV). A dual luciferase assay in which the reporter contained wild-type 3′ untranslated region (UTR) of ATM was performed. U87MG cells were infected with miR-223 or EV to establish the overexpressed stable cell lines (U87-223 or U87-EV, respectively). Cells were irradiated in vitro, and dose enhancement ratios at 2 Gy (DER{sub 2}) were calculated. Hind legs of BALB/c athymic mice were injected with U87-223 or U87-EV cells; after 2 weeks, half of the tumors were irradiated. Tumor volumes were tracked for a total of 5 weeks. Results: The dual luciferase reporter assay showed a significant reduction in luciferase activity of 293T cells cotransfected with miR-223 and the ATM 3′UTR compared to that in EV control. Overexpression of miR-223 in U87MG cells showed that ATM expression was significantly downregulated in the U87-223 cells compared to that in U87-EV (ATM/β-actin mRNA 1.0 vs 1.5, P<.05). U87-223 cells were hypersensitive to radiation compared to U87-EV cells in vitro (DER{sub 2} = 1.32, P<.01). Mice injected with miR-223-expressing tumors had almost the same tumors after 3 weeks (1.5 cm{sup 3} vs 1.7 cm{sup 3}). However, irradiation significantly decreased tumor size in miR-223-expressing tumors compared to those in controls (0.033 cm{sup 3} vs 0.829 cm{sup 3}). Conclusions: miR-223 overexpression downregulates ATM expression and sensitizes U87 cells to radiation in vitro and in vivo. MicroRNA-223 may be a novel cancer-targeting therapy, although its cancer- and patient-specific roles are

  18. T-cell ALL in ataxia telangiectasia cured with only 7 weeks of anti-leukemic therapy

    DEFF Research Database (Denmark)

    Hersby, Ditte S; Sehested, Astrid; Kristensen, Kim

    2015-01-01

    A 20-month-old girl diagnosed with T-cell acute lymphoblastic leukemia was treated according to the Nordic NOPHO ALL2000 protocol. The patient developed severe immunosuppression and experienced life-threatening adenovirus infection, which was treated with ribavirin and cidofovir. α-fetoprotein wa......A 20-month-old girl diagnosed with T-cell acute lymphoblastic leukemia was treated according to the Nordic NOPHO ALL2000 protocol. The patient developed severe immunosuppression and experienced life-threatening adenovirus infection, which was treated with ribavirin and cidofovir. α...

  19. Eye movements in ataxia-telangiectasia.

    Science.gov (United States)

    Baloh, R W; Yee, R D; Boder, E

    1978-11-01

    The spectrum of eye movement disorders in six patients with ataxia-telangiectasia at different stages of progression was assessed quantitatively by electrooculography. All patients demonstrated abnormalities of voluntary and involuntary saccades. The youngest and least involved patient had significantly increased reaction times of voluntary saccades, but normal accuracy and velocity. The other patients demonstrated increased reaction times and marked hypometria of horizontal and vertical voluntary saccades. Saccade velocity remained normal. Vestibular and optokinetic fast components (involuntary saccades) had normal amplitude and velocity but the eyes deviated tonically in the direction of the slow component. We conclude that patients with ataxia-telangiectasia have a defect in the initiation of voluntary and involuntary saccades in the earliest stages. These findings are distinctly different from those in other familial cerebellar atrophy syndromes.

  20. Clinical variability in ataxia-telangiectasia.

    Science.gov (United States)

    Lohmann, Ebba; Krüger, Stefanie; Hauser, Ann-Kathrin; Hanagasi, Hasmet; Guven, Gamze; Erginel-Unaltuna, Nihan; Biskup, Saskia; Gasser, Thomas

    2015-07-01

    Ataxia-telangiectasia (A-T) is an autosomal recessive inherited disease characterized by progressive childhood-onset cerebellar ataxia, oculomotor apraxia, choreoathetosis and telangiectasias of the conjunctivae. Further symptoms may be immunodeficiency and frequent infections, and an increased risk of malignancy. As well as this classic manifestation, several other non-classic forms exist, including milder or incomplete A-T phenotypes caused by homozygous or compound heterozygous mutations in the ATM gene. Recently, ATM mutations have been found in 13 Canadian Mennonites with early-onset, isolated, predominantly cervical dystonia, in a French family with generalized dystonia and in an Indian family with dopa-responsive cervical dystonia. In this article, we will describe a Turkish family with three affected sibs. Their phenotypes range from pure cervical dystonia associated with hand tremor to truncal and more generalized dystonic postures. Exome sequencing has revealed the potentially pathogenic compound heterozygous variants p.V2716A and p.G301VfsX19 in the ATM gene. The variants segregated perfectly with the phenotypes within the family. Both mutations detected in ATM have been shown to be pathogenic, and the α-fetoprotein, a marker of ataxia telangiectasia, was found to be increased. This report supports recent literature showing that ATM mutations are not exclusively associated with A-T but may also cause a more, even intra-familial variable phenotype in particular in association with dystonia.

  1. DNA synthesis in ataxia telangiectasia

    OpenAIRE

    Jaspers, Nicolaas

    1985-01-01

    textabstractAfter the discovery that cultured cells from AT patients are hypersensitive to ionizing radiation the suggestion was made that AT-could be the 1 X-ray-analogue 1 of xeroderma pigmentosum. The latter syndrome (XP) is characterized by hypersensitivity to short-wave UV-radiation, caused by a reduced ability to properly remove UV-induced DNA damage. The evidence for a DNA repair defect in AT cells is not as strong as in the case of XP (see section 2.2.5 of this thesis). Different XP p...

  2. DNA synthesis in ataxia telangiectasia

    NARCIS (Netherlands)

    N.G.J. Jaspers (Nicolaas)

    1985-01-01

    textabstractAfter the discovery that cultured cells from AT patients are hypersensitive to ionizing radiation the suggestion was made that AT-could be the 1 X-ray-analogue 1 of xeroderma pigmentosum. The latter syndrome (XP) is characterized by hypersensitivity to short-wave UV-radiation, caused by

  3. Neuropathology in classical and variant ataxia-telangiectasia.

    NARCIS (Netherlands)

    Verhagen, M.M.M.; Martin, J.J.; Deuren, M. van; Ceuterick-de Groote, C.; Weemaes, C.M.R.; Kremer, B.; Taylor, M.A.; Willemsen, M.A.A.P.; Lammens, M.M.Y.

    2012-01-01

    Ataxia-telangiectasia (A-T) is classically characterized by progressive neurodegeneration, oculocutaneous telangiectasia, immunodeficiency and elevated alpha-fetoprotein levels. Some patients, classified as variant A-T, exhibit a milder clinical course. In the latter patients extrapyramidal symptoms

  4. Síndrome de Ataxia-Telangiectasia

    Directory of Open Access Journals (Sweden)

    Amauri Batista da Silva

    1971-06-01

    Full Text Available A ataxia-telangiectasia, doença de Mme. Louis-Bar, é caracterizada pela associação de ataxia cerebelar progressiva, em geral com início na primeira infância, telangiectasas óculo-cutâneas, movimentos coreoatetósicos, tendência a infecções repetidas do sistema respiratório, retardo estaturo-ponderal, demenciação. São mais ou menos freqüentes os tumores do sistema reticuloendotelial. A doença é geralmente familiar, transmitida por genes recessivos, autossômicos, não ligados ao sexo. A alteração bioquímica mais encontrada consiste na diminuição ou ausência completa da fração A das gamaglobulinas, bem como na perturbação das reações de hipersensibilidade retardada. Os AA. relatam o estudo clínico, biológico e pneumencefalográfico de uma criança de 3 anos de idade, apresentando essa enfermidade desde os 18 meses de vida, sem antecedentes familiares.

  5. Chromosome instability and oxidative stress markers in patients with ataxia telangiectasia and their parents.

    Science.gov (United States)

    Ludwig, Luciane Bitelo; Valiati, Victor Hugo; Palazzo, Roberta Passos; Jardim, Laura Bannach; da Rosa, Darlan Pase; Bona, Silvia; Rodrigues, Graziela; Marroni, Norma Possa; Prá, Daniel; Maluf, Sharbel Weidner

    2013-01-01

    Ataxia telangiectasia (AT) is a rare neurodegenerative disorder, inherited in an autosomal recessive manner. Total blood samples were collected from 20 patients with AT, 13 parents of patients, and 17 healthy volunteers. This study aimed at evaluating the frequency of chromosomal breaks in spontaneous cultures, induced by bleomycin and ionizing radiation, and further evaluated the rates of oxidative stress in AT patients and in their parents, compared to a control group. Three cell cultures were performed to each individual: the first culture did not receive induction to chromosomal instability, the second was exposed to bleomycin, and the last culture was exposed to ionizing radiation. To evaluate the rates of oxidative stress, the markers superoxide dismutase (SOD), catalase (CAT), and thiobarbituric acid (TBARS) were utilized. Significant differences were observed between the three kinds of culture treatments (spontaneous, bleomycin, and radiation induced) and the breaks and chromosomal aberrations in the different groups. The oxidative stress showed no significant differences between the markers. This study showed that techniques of chromosomal instability after the induction of ionizing radiation and bleomycin are efficient in the identification of syndrome patients, with the ionizing radiation being the most effective.

  6. Neurodegeneration in ataxia-telangiectasia is caused by horror autotoxicus.

    Science.gov (United States)

    Kuljis, R O; Aguila, M C

    1999-05-01

    Ataxia-telangiectasia (A-T) is a pleiotropic, multi-system disorder with manifestations that include immune deficiency, sensitivity to ionizing radiation and neoplasms. Many of these manifestations are understood in principle since the identification in A-T patients of mutations in a gene encoding a protein kinase that plays a key role in signaling and repair of DNA damage. However, the cause of the neurodegeneration that afflicts patients with A-T for at least a decade before they succumb to overwhelming infections or malignancy remains mysterious. Based on our work in a mouse model of A-T and previous evidence of extra-neural autoimmune disorders in A-T, we postulate that the neurodegenerative process in A-T is not due to a function for A-T mutated (ATM) essential for the postnatal brain, but to an autoimmune process (hence 'horror autotoxicus', Paul Ehrlich's term for autoimmune disorder). This hypothetical mechanism may be analogous to that in the so-called 'paraneoplastic' neurodegenerative syndromes in patients with various malignancies. Thus, alterations in the balance between cellular and humoral immunity in A-T probably result in autoantibodies to cerebral epitopes shared with cells of the immune system. This hypothesis has important implications for the understanding and development of effective palliative and even preventative strategies for A-T, and probably for other so far relentlessly progressive neurodegenerative disorders.

  7. Molecular basis of ataxia telangiectasia and related diseases

    Institute of Scientific and Technical Information of China (English)

    Lindsay G BALL; Wei XIAO

    2005-01-01

    Ataxia telangiectasia (AT) is a rare human disease characterized by extreme cellular sensitivity to radiation and a predisposition to cancer, with a hallmark of onset in early childhood. Several human diseases also share similar symptoms with AT albeit with different degrees of severity and different associated disorders. While all AT patients contain mutations in the AT-mutated gene (ATM), most other ATlike disorders are defective in genes encoding an MRN protein complex consisting of Mre11, Rad50 and Nbs1. Both ATM and MRN function as cellular sensors to DNA double-strand breaks, which lead to the recruitment and phosphorylation of an array of substrate proteins involved in DNA repair, apoptosis and cell-cycle checkpoints, as well as gene regulation, translation initiation and telomere maintenance. ATM is a member of the family of phosphatidylinositol 3-kinase-like protein kinases (PIKK), and the discovery of many ATM substrates provides the underlying mechanisms of heterologous symptoms among AT patients. This review article focuses on recent findings related to the initial recognition of doublestrand breaks by ATM and MRN, as well as a DNA-dependent protein kinase complex consisting of the heterodimer Ku70/Ku80 and its catalytic subunit DNAPKcs, another member of PIKK. This possible interaction suggests that a much greater complex is involved in sensing, transducing and co-ordinating cellular events in response to genome instability.

  8. Neuropathology in classical and variant ataxia-telangiectasia

    NARCIS (Netherlands)

    Verhagen, Mijke M. M.; Martin, Jean-Jacques; van Deuren, Marcel; Groote, Chantal Ceuterick-de; Weemaes, Corry M. R.; Kremer, Berry H. P. H.; Taylor, Malcolm A. R.; Willemsen, Michel A. A. P.; Lammens, Martin

    2012-01-01

    Ataxia-telangiectasia (A-T) is classically characterized by progressive neurodegeneration, oculocutaneous telangiectasia, immunodeficiency and elevated a-fetoprotein levels. Some patients, classified as variant A-T, exhibit a milder clinical course. In the latter patients extrapyramidal symptoms, in

  9. Clinical spectrum of ataxia-telangiectasia in adulthood.

    NARCIS (Netherlands)

    Verhagen, M.M.; Abdo, W.; Willemsen, M.A.A.P.; Hogervorst, F.B.L.; Smeets, D.F.C.M.; Hiel, J.A.P.; Brunt, E.R.; Rijn, M.A. van; Majoor Krakauer, D.; Oldenburg, R.A.; Broeks, A.; Last, J.I.; Veer, L.J. van 't; Tijssen, M.A.; Dubois, A.M.; Kremer, H.P.H.; Weemaes, C.M.R.; Taylor, A.M.; Deuren, M. van

    2009-01-01

    OBJECTIVE: To describe the phenotype of adult patients with variant and classic ataxia-telangiectasia (A-T), to raise the degree of clinical suspicion for the diagnosis variant A-T, and to assess a genotype-phenotype relationship for mutations in the ATM gene. METHODS: Retrospective analysis of the

  10. Clinical spectrum of ataxia-telangiectasia in adulthood

    NARCIS (Netherlands)

    Verhagen, M M M; Abdo, W F; Willemsen, M A A P; Hogervorst, F B L; Smeets, D F C M; Hiel, J A P; Brunt, E R; van Rijn, M A; Majoor Krakauer, D; Oldenburg, R A; Broeks, A; Last, J I; van't Veer, L J; Tijssen, M A J; Dubois, A M I; Kremer, H P H; Weemaes, C M R; Taylor, A M R; van Deuren, M

    2009-01-01

    OBJECTIVE: To describe the phenotype of adult patients with variant and classic ataxia-telangiectasia (A-T), to raise the degree of clinical suspicion for the diagnosis variant A-T, and to assess a genotype-phenotype relationship for mutations in the ATM gene. METHODS: Retrospective analysis of the

  11. Disorders of Upper Limb Movements in Ataxia-Telangiectasia.

    Directory of Open Access Journals (Sweden)

    Aasef G Shaikh

    Full Text Available Ataxia-telangiectasia is known for cerebellar degeneration, but clinical descriptions of abnormal tone, posture, and movements suggest involvement of the network between cerebellum and basal ganglia. We quantitatively assessed the nature of upper-limb movement disorders in ataxia-telangiectasia. We used a three-axis accelerometer to assess the natural history and severity of abnormal upper-limb movements in 80 ataxia-telangiectasia and 19 healthy subjects. Recordings were made during goal-directed movements of upper limb (kinetic task, while arms were outstretched (postural task, and at rest. Almost all ataxia-telangiectasia subjects (79/80 had abnormal involuntary movements, such as rhythmic oscillations (tremor, slow drifts (dystonia or athetosis, and isolated rapid movements (dystonic jerks or myoclonus. All patients with involuntary movements had both kinetic and postural tremor, while 48 (61% also had resting tremor. The tremor was present in transient episodes lasting several seconds during two-minute recording sessions of all three conditions. Percent time during which episodic tremor was present was greater for postural and kinetic tasks compared to rest. Resting tremor had higher frequency but smaller amplitude than postural and kinetic tremor. Rapid non-rhythmic movements were minimal during rest, but were triggered during sustained arm postures and goal directed arm movements suggesting they are best considered a form of dystonic jerks or action myoclonus. Advancing age did not correlate with the severity of involuntary limb movements. Abnormal upper-limb movements in ataxia-telangiectasia feature classic cerebellar impairment, but also suggest involvement of the network between the cerebellum and basal ganglia.

  12. The effect of ataxia-telangiectasia mutated kinase-dependent hyperphosphorylation of checkpoint kinase-2 on oligodeoxynucleotide 7909 containing CpG motifs-enhanced sensitivity to X-rays in human lung adenocarcinoma A549 cells

    Directory of Open Access Journals (Sweden)

    Liu XQ

    2015-06-01

    Full Text Available Xiaoqun Liu,1,* Xiangdong Liu,2,* Tiankui Qiao,1 Wei Chen,1 Sujuan Yuan1 1Department of Oncology, 2Department of Ophthalmology, Affiliated Jinshan Hospital, Fudan University, Shanghai, People’s Republic of China *These authors contributed equally to this work Objective: The aim of the study reported here was to further investigate the potential effect of ataxia-telangiectasia mutated (ATM kinase-dependent hyperphosphorylation of checkpoint kinase-2 (Chk2 on radiosensitivity enhanced by oligodeoxynucleotide 7909 containing CpG motifs (CpG ODN7909 in human lung adenocarcinoma A549 cells. Methods: In vitro A549 cells were randomly separated into control, CpG, X-ray, CpG+X-ray, ATM kinase-small interfering RNA (siRNA+CpG+X-ray (ATM-siRNA, and Chk2-siRNA+CpG+X-ray (Chk2-siRNA groups. siRNAs were adopted to silence the ATM and Chk2 genes. Expression and phosphorylation of ATM kinase and Chk2 were detected by Western blot assay. Cell colonies were observed under inverted phase-contrast microscopy. Cellular survival curves were fitted using a multi-target single-hitting model. Cell cycle and apoptosis were analyzed by flow cytometry. Results: Expression of ATM kinase and Chk2 was similar among the control, CpG, X-ray, and CpG+X-ray groups. Phosphorylated ATM kinase and Chk2 were significantly increased in the CpG+X-ray group compared with in the X-ray group (t=6.00, P<0.01 and t=3.13, P<0.05, respectively, though these were hardly detected in the control and CpG groups. However, expression of ATM kinase and Chk2 was clearly downregulated in the ATM-siRNA and Chk2-siRNA groups, respectively. Similarly, their phosphorylation levels were also significantly decreased in the ATM-siRNA group (t=14.35, P<0.01 and t=8.46, P<0.01, respectively and a significant decrease in phosphorylated Chk2 was observed in the Chk2-siRNA group (t=7.28, P<0.01 when compared with the CpG+X-ray group. Further, the number of A549 cells at Gap 2/mitotic phase and the apoptosis

  13. Ataxia telangiectasia and Nijmegen breakage syndrome : neurological, immunological and genetic aspects

    NARCIS (Netherlands)

    Hiel, J.A.P.

    2004-01-01

    Ataxia telangiectasia (AT) and Nijmegen breakage syndrome (NBS) are rare autosomal recessive conditions caused by mutations in respectively ATM and NBS1. The encoding proteins ATM and nibrin are involved in the processing of DNA damage and maintenance of genomic stability. Ataxia telangiectasia is d

  14. Ataxia-telangiectasia: some historic, clinical and pathologic observations.

    Science.gov (United States)

    Boder, E

    1975-01-01

    Although an isolated clinical case report was published in 1926 and another in 1941, ataxia-telangiectasia (A-T) was not established as a distinct entity until 1957, when it was first delineated clinicopathologically. Susceptibility to sinopulmonary infection was identified as the main cause of death and as the third major component of the syndrome; its heredofamilial nature was documented, and it was designated "ataxia-telangiectasia." In a later review of 101 published cases, lymphoreticular malignancy emerged as the second most frequent cause of death. Although the thymus was found to be absent in the first reported autopsy in 1957 and the serum IgA deficiency was first recorded in 1961, A-T was not established as an immunodeficiency disease until 1963. Thymic abnormality and dysgammaglobulinemia explain the 2 main causes of death, sinopulmonary and neoplastic, but the immunodeficiency is probably not the central defect. It does not appear to explain either of the 2 main clinical diagnostic keys, the ataxia and the telangiectasia, or any of the other seemingly unrealted multisystemic facets of this complex disorder. Some of our most provocative long-term clinical observations and recent pathologic findings in our series of 9 autopsies are discussed.

  15. Unusual and severe disease course in a child with ataxia-telangiectasia.

    NARCIS (Netherlands)

    Meyts, I.; Weemaes, C.M.R.; Wolf-Peeters, C. de; Proesmans, M.; Renard, M.; Uyttebroeck, A.; Boeck, K. de

    2003-01-01

    Ataxia-telangiectasia (AT) is an autosomal recessive syndrome of combined immunodeficiency. Hallmarks of the disease comprise progressive cerebellar ataxia, oculocutaneous telangiectasia, cancer susceptibility and variable humoral and cellular immunodeficiency. We describe a patient with AT presenti

  16. Brain glucose metabolism in adults with ataxia-telangiectasia and their asymptomatic relatives.

    Science.gov (United States)

    Volkow, Nora D; Tomasi, Dardo; Wang, Gene-Jack; Studentsova, Yana; Margus, Brad; Crawford, Thomas O

    2014-06-01

    Ataxia-telangiectasia is a recessive genetic disorder (ATM is the mutated gene) of childhood with severe motor impairments and whereas homozygotes manifest the disorder, heterozygotes are asymptomatic. Structural brain imaging and post-mortem studies in individuals with ataxia-telangiectasia have reported cerebellar atrophy; but abnormalities of motor control characteristic of extrapyramidal dysfunction suggest impairment of broader motor networks. Here, we investigated possible dysfunction in other brain areas in individuals with ataxia-telangiectasia and tested for brain changes in asymptomatic relatives to assess if heterozygocity affects brain function. We used positron emission tomography and (18)F-fluorodeoxyglucose to measure brain glucose metabolism (quantified as µmol/100 g/min), which serves as a marker of brain function, in 10 adults with ataxia-telangiectasia, 19 non-affected adult relatives (12 siblings, seven parents) and 29 age-matched healthy controls. Statistical parametric mapping and region of interest analyses were used to compare individuals with ataxia-telangiectasia, asymptomatic relatives, and unrelated controls. We found that participants with ataxia-telangiectasia had lower metabolism in cerebellar hemispheres (14%, P brain stimulation. Our finding of decreased metabolism in vermis and hippocampus of asymptomatic relatives suggests that heterozygocity influences the function of these brain regions.

  17. Multi-drugs resistant acne rosacea in a child affected by Ataxia-Telangiectasia: successful treatment with Isotretinoin.

    Science.gov (United States)

    Cantarutti, Nicoletta; Claps, Alessia; Angelino, Giulia; Chessa, Luciana; Callea, Francesco; El Hachem, May; Diociaiuti, Andrea; Finocchi, Andrea

    2015-03-28

    Ataxia-Telangiectasia is a rare multisystem autosomal recessive disorder [OMIM 208900], caused by mutations in Ataxia-Telangiectasia Mutated gene. It is characterized by neurological, immunological and cutaneous involvement. Granulomas have been previously reported in Ataxia-Telangiectasia patients, even if acne rosacea has not been described.We report a case of a young Ataxia-Telangiectasia patient with a severe immunological and neurological involvement, who developed granulomatous skin lesions diagnosed by skin biopsy as acne rosacea. Considering the severe clinical picture and the lack of improvement to multiple topic and systemic therapies, treatment with Isotretinoin was started and the skin lesions disappeared after five months. However the therapy was stopped due to drug-hepatotoxicity.Systemic treatment with Isotretinoin should be carefully considered in patient with Ataxia-Telangiectasia for the treatment of multi-drug resistant acne rosacea, however its toxicity may limit long-term use and the risk/benefit ratio of the treatment should be evaluated.

  18. Role of ataxia-telangiectasia mutated (ATM) in porcine oocyte in vitro maturation.

    Science.gov (United States)

    Lin, Zi-Li; Kim, Nam-Hyung

    2015-06-01

    Ataxia-telangiectasia mutated (ATM) is critical for the DNA damage response, cell cycle checkpoints, and apoptosis. Significant effort has focused on elucidating the relationship between ATM and other nuclear signal transducers; however, little is known about the connection between ATM and oocyte meiotic maturation. We investigated the function of ATM in porcine oocytes. ATM was expressed at all stages of oocyte maturation and localized predominantly in the nucleus. Furthermore, the ATM-specific inhibitor KU-55933 blocked porcine oocyte maturation, reducing the percentages of oocytes that underwent germinal vesicle breakdown (GVBD) and first polar body extrusion. KU-55933 also decreased the expression of DNA damage-related genes (breast cancer 1, budding uninhibited by benzimidazoles 1, and P53) and reduced the mRNA and protein levels of AKT and other cell cycle-regulated genes that are predominantly expressed during G2/M phase, including bone morphogenetic protein 15, growth differentiation factor 9, cell division cycle protein 2, cyclinB1, and AKT. KU-55933 treatment decreased the developmental potential of blastocysts following parthenogenetic activation and increased the level of apoptosis. Together, these data suggested that ATM influenced the meiotic and cytoplasmic maturation of porcine oocytes, potentially by decreasing their sensitivity to DNA strand breaks, stimulating the AKT pathway, and/or altering the expression of other maternal genes.

  19. Cutaneous granulomatosis and combined immunodeficiency revealing Ataxia-Telangiectasia: a case report

    OpenAIRE

    Antoccia Antonio; Ferrari Francesca; Angelino Giulia; Scarselli Alessia; Folgori Laura; Chessa Luciana; Finocchi Andrea

    2010-01-01

    Abstract Ataxia-telangiectasia (A-T) is a complex multisystem disorder characterized by progressive neurological impairment, variable immunodeficiency and oculo-cutaneous telangiectasia. A-T is a member of chromosomal breakage syndromes and it is caused by a mutation in the ataxia-telangiectasia mutated (ATM) gene. Because of a wide clinical heterogeneity, A-T is often difficult to diagnose in children. We report an unusual case of a 3-year-old boy affected by A-T who presented exclusively wi...

  20. The role of the neuro-astro-vascular unit in the etiology of Ataxia Telangiectasia

    Directory of Open Access Journals (Sweden)

    Leenoy eMeshulam

    2012-09-01

    Full Text Available The growing recognition that brain pathologies do not affect neurons only but rather are, to a large extent, pathologies of glial cells as well as of the vasculature opens to new perspectives in our understanding of genetic disorders of the CNS. To validate the role of the neuron-glial-vascular unit in the etiology of genome instability disorders, we report about cell death and morphological aspects of neuro-glia networks and the associated vasculature in a mouse model of Ataxia Telangiectasia (A-T, a human genetic disorder that induces severe motor impairment. We found that AT-mutated protein deficiency was consistent with aberrant astrocytic morphology and alterations of the vasculature, often accompanied by reactive gliosis. Interestingly similar findings could also be reported in the case of other genetic disorders. These observations bolster the notion that astrocyte-specific pathologies, hampered vascularization and astrocyte-endothelium interactions in the CNS could play a crucial role in the etiology of genome instability brain disorders and could underlie neurodegeneration.

  1. A single ataxia telangiectasia gene with a product similar to PI-3 kinase

    Energy Technology Data Exchange (ETDEWEB)

    Savitsky, K.; Bar-Shira, A.; Gilad, S.; Rotman, G.; Ziv, Y.; Vanagaite, L.; Smith, S.; Uziel, T.; Sfez, S.; Ashkenazi, M. [Tel Aviv Univ. (Israel)] [and others

    1995-06-23

    A gene, ATM, that is mutated in the autosomal recessive disorder ataxia telangiectasia (AT) was identified by positional cloning on chromosome 11q22-23. AT is characterized by cerebellar degeneration, immunodeficiency, chromosomal instability, cancer predisposition, radiation sensitivity, and cell cycle abnormalities. The disease is genetically heterogeneous, with four complementation groups that have been suspected to represent different genes. ATM, which has a transcript of 12 kilobases, was found to be mutated in AT patients from all complementation groups, indicating that it is probably the sole gene responsible for this disorder. A partial ATM complementary DNA clone of 5.9 kilobases encoded a putative protein that is similar to several yeast and mammalian phosphatidylinositol-3{prime} kinases that are involved in mitogenic signal transduction, meiotic recombination, and cell cycle control. The discovery of ATM should enhance understanding of AT and related syndromes and may allow the identification of AT heterozygotes, who are at increased risk of cancer. 54 refs., 5 figs., 1 tab.

  2. Role of chromatin structure modulation by the histone deacetylase inhibitor trichostatin A on the radio-sensitivity of ataxia telangiectasia

    Energy Technology Data Exchange (ETDEWEB)

    Meschini, Roberta, E-mail: meschini@unitus.it; Morucci, Elisa; Berni, Andrea; Lopez-Martinez, Wilner; Palitti, Fabrizio

    2015-07-15

    Highlights: • Role of chromatin compaction on chromosomal instability. • Reduced radiation-induced clastogenicity in Ataxia telangiectasia cell lines. • Histone tails hyperacetylation reduces heterochromatin content favouring DSBs repair. - Abstract: At present, a lot is known about biochemical aspects of double strand breaks (DBS) repair but how chromatin structure affects this process and the sensitivity of DNA to DSB induction is still an unresolved question. Ataxia telangiectasia (A-T) patients are characterised by very high sensitivity to DSB-inducing agents such as ionising radiation. This radiosensitivity is revealed with an enhancement of chromosomal instability as a consequence of defective DNA repair for a small fraction of breaks located in the heterochromatin, where they are less accessible. Besides, recently it has been reported that Ataxia Telangiectasia Mutated (ATM) mediated signalling modifies chromatin structure. In order to study the impact of chromatin compaction on the chromosomal instability of A-T cells, the response to trichostatin-A, an histone deacetylase inhibitor, in normal and A-T lymphoblastoid cell lines was investigated testing its effect on chromosomal aberrations, cell cycle progression, DNA damage and repair after exposure to X-rays. The results suggest that the response to both trichostatin-A pre- and continuous treatments is independent of the presence of either functional or mutated ATM protein, as the reduction of chromosomal damage was found also in the wild-type cell line. The presence of trichostatin-A before exposure to X-rays could give rise to prompt DNA repair functioning on chromatin structure already in an open conformation. Differently, trichostatin-A post-treatment causing hyperacetylation of histone tails and reducing the heterochromatic DNA content might diminish the requirement for ATM and favour DSBs repair reducing chromosomal damage only in A-T cells. This fact could suggest that trichostatin-A post

  3. A novel porcine model of ataxia telangiectasia reproduces neurological features and motor deficits of human disease.

    Science.gov (United States)

    Beraldi, Rosanna; Chan, Chun-Hung; Rogers, Christopher S; Kovács, Attila D; Meyerholz, David K; Trantzas, Constantin; Lambertz, Allyn M; Darbro, Benjamin W; Weber, Krystal L; White, Katherine A M; Rheeden, Richard V; Kruer, Michael C; Dacken, Brian A; Wang, Xiao-Jun; Davis, Bryan T; Rohret, Judy A; Struzynski, Jason T; Rohret, Frank A; Weimer, Jill M; Pearce, David A

    2015-11-15

    Ataxia telangiectasia (AT) is a progressive multisystem disorder caused by mutations in the AT-mutated (ATM) gene. AT is a neurodegenerative disease primarily characterized by cerebellar degeneration in children leading to motor impairment. The disease progresses with other clinical manifestations including oculocutaneous telangiectasia, immune disorders, increased susceptibly to cancer and respiratory infections. Although genetic investigations and physiological models have established the linkage of ATM with AT onset, the mechanisms linking ATM to neurodegeneration remain undetermined, hindering therapeutic development. Several murine models of AT have been successfully generated showing some of the clinical manifestations of the disease, however they do not fully recapitulate the hallmark neurological phenotype, thus highlighting the need for a more suitable animal model. We engineered a novel porcine model of AT to better phenocopy the disease and bridge the gap between human and current animal models. The initial characterization of AT pigs revealed early cerebellar lesions including loss of Purkinje cells (PCs) and altered cytoarchitecture suggesting a developmental etiology for AT and could advocate for early therapies for AT patients. In addition, similar to patients, AT pigs show growth retardation and develop motor deficit phenotypes. By using the porcine system to model human AT, we established the first animal model showing PC loss and motor features of the human disease. The novel AT pig provides new opportunities to unmask functions and roles of ATM in AT disease and in physiological conditions.

  4. Ataxia telangiectasia mutated activation by transcription- and topoisomerase I-induced DNA double-strand breaks.

    Science.gov (United States)

    Sordet, Olivier; Redon, Christophe E; Guirouilh-Barbat, Josée; Smith, Susan; Solier, Stéphanie; Douarre, Céline; Conti, Chiara; Nakamura, Asako J; Das, Benu B; Nicolas, Estelle; Kohn, Kurt W; Bonner, William M; Pommier, Yves

    2009-08-01

    Ataxia telangiectasia mutated (ATM), the deficiency of which causes a severe neurodegenerative disease, is a crucial mediator for the DNA damage response (DDR). As neurons have high rates of transcription that require topoisomerase I (TOP1), we investigated whether TOP1 cleavage complexes (TOP1cc)-which are potent transcription-blocking lesions-also produce transcription-dependent DNA double-strand breaks (DSBs) with ATM activation. We show the induction of DSBs and DDR activation in post-mitotic primary neurons and lymphocytes treated with camptothecin, with the induction of nuclear DDR foci containing activated ATM, gamma-H2AX (phosphorylated histone H2AX), activated CHK2 (checkpoint kinase 2), MDC1 (mediator of DNA damage checkpoint 1) and 53BP1 (p53 binding protein 1). The DSB-ATM-DDR pathway was suppressed by inhibiting transcription and gamma-H2AX signals were reduced by RNase H1 transfection, which removes transcription-mediated R-loops. Thus, we propose that Top1cc produce transcription arrests with R-loop formation and generate DSBs that activate ATM in post-mitotic cells.

  5. Motor pathway degeneration in young ataxia telangiectasia patients: A diffusion tractography study

    Directory of Open Access Journals (Sweden)

    Ishani Sahama

    2015-01-01

    Conclusions: Whole tract analysis of the corticomotor, corticospinal and somatosensory pathways in ataxia telangiectasia showed significant white matter degeneration along the entire length of motor circuits, highlighting that ataxia–telangiectasia gene mutation impacts the cerebellum and multiple other motor circuits in young patients.

  6. NAD(+) Replenishment Improves Lifespan and Healthspan in Ataxia Telangiectasia Models via Mitophagy and DNA Repair

    DEFF Research Database (Denmark)

    Fang, Evandro Fei; Kassahun, Henok; Croteau, Deborah L

    2016-01-01

    Ataxia telangiectasia (A-T) is a rare autosomal recessive disease characterized by progressive neurodegeneration and cerebellar ataxia. A-T is causally linked to defects in ATM, a master regulator of the response to and repair of DNA double-strand breaks. The molecular basis of cerebellar atrophy...

  7. Distal spinal muscular atrophy as a major feature in adult-onset ataxia telangiectasia.

    NARCIS (Netherlands)

    Hiel, J.A.P.; Engelen, B.G.M. van; Weemaes, C.M.R.; Broeks, A.; Verrips, A.; Laak, H.J. ter; Vingerhoets, H.M.; Heuvel, L.P.W.J. van den; Lammens, M.M.Y.; Gabreëls, F.J.M.; Last, J.I.; Taylor, A.M.R.

    2006-01-01

    The authors report four adult-onset ataxia telangiectasia (AT) patients belonging to two families lacking pronounced cerebellar ataxia but displaying distal spinal muscular atrophy. AT was proven by genetic studies showing ATM mutations and a reduced level of ATM. ATM activity, as measured by phosph

  8. Cognitive and speech-language performance in children with ataxia telangiectasia

    NARCIS (Netherlands)

    Vinck, Anja; Verhagen, Mijke M. M.; van Gerven, Marjo; de Groot, Imelda J. M.; Weemaes, Corry M. R.; Maassen, Ben A. M.; Willemsen, Michel A. A. P.

    2011-01-01

    Objective: To describe cognitive and speech-language functioning of patients with ataxia-telangiectasia (A-T) in relation to their deteriorating (oculo)motor function. Design: Observational case series. Methods: Cognitive functioning, language, speech and oral-motor functioning were examined in eigh

  9. Cognitive and speech-language performance in children with ataxia telangiectasia

    NARCIS (Netherlands)

    Vinck, A.; Verhagen, M.M.; Gerven, M.; Groot, I.J.M. de; Weemaes, C.M.R.; Maassen, B.A.M.; Willemsen, M.A.A.P.

    2011-01-01

    OBJECTIVE: To describe cognitive and speech-language functioning of patients with ataxia-telangiectasia (A-T) in relation to their deteriorating (oculo)motor function. DESIGN: Observational case series. METHODS: Cognitive functioning, language, speech and oral-motor functioning were examined in eigh

  10. Nucleotide sequence analysis of a candidate gene for ataxia-telangiectasia group D (ATDC)

    Energy Technology Data Exchange (ETDEWEB)

    Leonhardt, E.A.; Kapp, L.N.; Young, B.R.; Murnane, J.P. (Univ. of California, San Francisco, CA (United States))

    1994-01-01

    A radioresistant cell clone (1B3) was previously isolated after transfection of an ataxia-telangiectasia (AT) group D cell line with a human cosmid library. A cosmid rescued from the integration site in 1B3 contained human DNA from chromosome position 11q23, the same region shown by both genetic linkage and chromosome transfer to contain the genes for AT complementation groups A/B, C, and D. A gene within the cosmid (ATDC) was found to produce mRNAs of different sizes. A cDNA for one of the most abundant mRNAs (3.0 kb) was isolated from a HeLa cell library. In the present study, the authors sequenced the 3.0-kb cDNA and the surrounding intron DNA in the cosmids. They used polymerase chain reaction, with primers in the introns, to confirm the number of exons and to analyze DNA from AT group D cells for mutations within this gene. Although no mutations were found, they do not rule out the possibility that mutations may be present within the regulatory sequences or coding sequences found in other mRNAs specific for this gene. From the sequence analysis, they found that the ATDC gene product is one of a group of proteins that share multiple zinc finger motifs and an adjacent leucine zipper motif. These proteins have been proposed to form homo- or hetero-dimers involved in nucleic acid binding, consistent with the fact that many of these proteins appear to be transcriptional regulatory factors involved in carcinogenesis and/or differentiation. The likelihood that the ATDC gene product is involved in transcriptional regulation could explain the pleiomorphic characteristics of AT, including abnormal cell cycle regulation. 36 refs., 5 figs., 2 tabs.

  11. Heterogeneity of chromosomal breakage levels in epithelial tissue of ataxia-telangiectasia homozygotes and heterozygotes.

    Science.gov (United States)

    Rosin, M P; Ochs, H D; Gatti, R A; Boder, E

    1989-09-01

    The objective of this study was to obtain an estimate of the frequency distribution of spontaneous chromosomal breakage occurring in vivo in oral epithelia of 20 ataxia-telangiectasia patients (A-T homozygotes) and 26 parents (A-T obligate heterozygotes). Samples of exfoliated cells were obtained from each individual by swabbing the oral cavity and preparing air-dried slides. The percentage of exfoliated cells with micronuclei (MEC frequency) was used as an in vivo indicator for the amount of chromosomal breakage occurring in the tissue. As a population group, MEC frequencies of the A-T patients differed significantly from controls (mean for A-T patients, 1.51; for controls, 0.29; P less than 0.01). However, the values observed in individual patients ranged from MEC frequencies 10- to 12-fold above control values, to frequencies overlapping the upper values observed in the controls. Similarly, MEC frequencies observed among the A-T heterozygotes differed significantly from controls (mean for A-T heterozygotes, 1.02, mean for controls, 0.29; P less than 0.01). However, only 16 of the 26 individuals sampled had MEC frequencies greater than 0.5%, the 90th percentile for controls (compared with 16 of the 20 A-T patients examined). Of the A-T patients 11 had been previously assigned to complementation groups on the basis of sensitivity to x-irradiation. Seven of the patients belonged to group A and had MEC frequencies ranging from 0.3% to 1.9% with the remaining patients belonging to group C with MEC frequencies of 0.2% to 0.9%. The data presented in this paper suggest that although levels of spontaneous breakage in epithelial tissues of A-T patients and A-T obligate heterozygotes are often significantly elevated, this is not the case in all individuals.

  12. Cutaneous granulomatosis and combined immunodeficiency revealing Ataxia-Telangiectasia: a case report

    Directory of Open Access Journals (Sweden)

    Antoccia Antonio

    2010-04-01

    Full Text Available Abstract Ataxia-telangiectasia (A-T is a complex multisystem disorder characterized by progressive neurological impairment, variable immunodeficiency and oculo-cutaneous telangiectasia. A-T is a member of chromosomal breakage syndromes and it is caused by a mutation in the ataxia-telangiectasia mutated (ATM gene. Because of a wide clinical heterogeneity, A-T is often difficult to diagnose in children. We report an unusual case of a 3-year-old boy affected by A-T who presented exclusively with extensive cutaneous granulomatosis and severe combined immunodeficiency, without neurological abnormalities, at the time of diagnosis. This case clearly emphasizes the variable presentation of A-T syndrome and highlights the difficulties in the early diagnosis of A-T. A-T should be considered in children with evidence of combined humoral and cellular immunodeficiency associated with unexplained skin granulomatous lesions, even in the absence of the classic features of this syndrome.

  13. Conjunctival Telangiectasia in a Patient with Ataxia Telangiectasia: A Case Report

    Directory of Open Access Journals (Sweden)

    Özge Pınar Akarsu

    2012-01-01

    Full Text Available The purpose of this paper is to report a 7-year-old patient who developed bilateral conjunctival hyperemia while being under treatment of pneumonia in Pediatric Infectious Diseases Clinic at Sisli Etfal Training and Research Hospital. Ophthalmological examination revealed bilateral conjunctival telangiectasias which were thought to be the ophthalmologic sign of ataxia telangiectasia after considering the other clinical findings, laboratory and imaging results, and family history. (Turk J Oph thal mol 2012; 42: 75-7

  14. Prenatal diagnosis of ataxia-telangiectasia and Nijmegen Breakage Syndrome by the assay of radioresistant DNA synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kleijer, W.J.; Kraan, M. van der; Los, F.J. [Erasmus Univ., Rotterdam (Netherlands). Dept. of Clinical Genetics; Jaspers, N.G.J. [Erasmus Univ., Rotterdam (Netherlands). Lab. of Cell Biology and Genetics

    1994-12-01

    Prenatal diagnosis was performed in 16 pregnancies at risk of ataxia-telangiectasia (A-T) or Nijmegen Breakage Syndrome (NBS). Radioresistant DNA synthesis (RDS) was investigated in cultured chorionic villus (CV) cells and/or amniotic fluid (AF) cells. In four pregnancies, an affected foetus was diagnosed with increased RDS in cultured CV cells. In three of the four cases confirmation of the diagnosis was obtained by analysis of AF cells and/or skin fibroblasts from the foetus cultured after termination of the pregnancy; in the fourth case a fibroblast culture from the aborted foetus failed. In one case, only AF cells could be analysed in a late stage of pregnancy; pregnancy was terminated due to intermediate/equivocal results but the foetus fibroblasts showed normal RDS. Normal RDS was demonstrated in the other 11 pregnancies at 25% risk either by analysis of CB cells (nine cases) or of AF cells (two cases). In some cases the (normal) results on the CV cells were corroborated by subsequent analysis of Af cells. The results suggest that RDS analysis of CV cells allows reliable prenatal diagnosis of A-T/NBS. However, amniocentesis may be necessary to confirm normal results on CV cells if the foetus is female (because of the risk of maternal cell contamination) or in the rare case of equivocal results. (author).

  15. DNA-dependent protein kinase regulates DNA end resection in concert with Mre11-Rad50-Nbs1 (MRN) and ataxia telangiectasia-mutated (ATM).

    Science.gov (United States)

    Zhou, Yi; Paull, Tanya T

    2013-12-27

    The resection of DNA double strand breaks initiates homologous recombination (HR) and is critical for genomic stability. Using direct measurement of resection in human cells and reconstituted assays of resection with purified proteins in vitro, we show that DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a classic nonhomologous end joining factor, antagonizes double strand break resection by blocking the recruitment of resection enzymes such as exonuclease 1 (Exo1). Autophosphorylation of DNA-PKcs promotes DNA-PKcs dissociation and consequently Exo1 binding. Ataxia telangiectasia-mutated kinase activity can compensate for DNA-PKcs autophosphorylation and promote resection under conditions where DNA-PKcs catalytic activity is inhibited. The Mre11-Rad50-Nbs1 (MRN) complex further stimulates resection in the presence of Ku and DNA-PKcs by recruiting Exo1 and enhancing DNA-PKcs autophosphorylation, and it also inhibits DNA ligase IV/XRCC4-mediated end rejoining. This work suggests that, in addition to its key role in nonhomologous end joining, DNA-PKcs also acts in concert with MRN and ataxia telangiectasia-mutated to regulate resection and thus DNA repair pathway choice.

  16. Patients with an inherited syndrome characterized by immunodeficiency, microcephaly, and chromosomal instability: genetic relationship to ataxia telangiectasia

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, N.G.; Taalman, R.D.; Baan, C.

    1988-01-01

    Fibroblast cultures from six unrelated patients having a familial type of immunodeficiency combined with microcephaly, developmental delay, and chromosomal instability were studied with respect to their response to ionizing radiation. The cells from five of them resembled those from individuals with ataxia telangiectasia (AT) in that they were two to three times more radiosensitive on the basis of clonogenic cell survival. In addition, after exposure to either X-rays or bleomycin, they showed an inhibition of DNA replication that was less pronounced than that in normal cells and characteristic of AT fibroblasts. However, the patients are clinically very different from AT patients, not showing any signs of neurocutaneous symptoms. Genetic complementation studies in fused cells, with the radioresistant DNA synthesis used as a marker, showed that the patients' cells could complement representatives of all presently known AT complementation groups. Furthermore, they were shown to constitute a genetically heterogeneous group as well. It is concluded that these patients are similar to AT patients with respect to cytological parameters. The clinical differences between these patients and AT patients are a reflection of genetic heterogeneity. The data indicate that the patients suffer from a chromosome-instability syndrome that is distinct from AT.

  17. A Precocious Cerebellar Ataxia and Frequent Fever Episodes in a 16-Month-Old Infant Revealing Ataxia-Telangiectasia Syndrome

    Directory of Open Access Journals (Sweden)

    Luigi Nespoli

    2013-01-01

    Full Text Available Ataxia-telangiectasia (AT is the most frequent progressive cerebellar ataxia in infancy and childhood. Immunodeficiency which includes both cellular and humoral arms has variable severity. Since the clinical presentation is extremely variable, a high clinical suspicion will allow an early diagnosis. Serum alpha-fetoprotein is elevated in 80–85% of patients and therefore could be used as a screening tool. Here, we present a case of a 5-year-old female infant who was admitted to our department at the age of 16 months because of gait disorders and febrile episodes that had begun at 5 months after the cessation of breastfeeding. Serum alfa-fetoprotein level was elevated. Other investigations showed leukocytopenia with lymphopenia, reduced IgG2 and IgA levels, and low titers of specific postimmunization antibodies against tetanus toxoid and Haemophilus B polysaccharide. Peripheral lymphocytes subsets showed reduction of T cells with a marked predominance of T cells with a memory phenotype and a corresponding reduction of naïve T cells; NK cells were very increased (41% with normal activity. The characterization of the ATM gene mutations revealed 2 specific mutations (c.5692C > T/c.7630-2A > C compatible with AT diagnosis. It was concluded that AT syndrome should be considered in children with precocious signs of cerebellar ataxia and recurrent fever episodes.

  18. Detection of aneuploidy in sperm of an ataxia telangiectasia patient using three-chromosome fluorescence in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, X.R.; Baulch, J.E. [Lawrence Livermore National Lab., CA (United States); Arnheim, N. [USC, Los Angeles, CA (United States)] [and others

    1994-09-01

    Ataxia telangiectasia (A-T) is an inherited, recessive, cancer-prone disorder. Fluorescence in situ hybridization (FISH) with DNA probes specific for three chromosomes was applied to sperm of an A-T patient to determine if there may be an increased germinal risk for aneuploidy. Air-dried sperm smears were treated with proteinase K and were decondensed with DTT and LIS. The slides were then hybridized with fluorescently labeled repetitive DNA probes specific for chromosomes X, Y and 8, and a total of 11,825 sperm cells were scored. The ratio of sperm bearing X-8 and Y-8 was 1:1, as predicted. The frequencies of hyperhaploidy were 3.9, 1.0, 17.6 and 7.8 per 10,000 cells for categories X-X-8, Y-Y-8, X-Y-8 and 8-8-(X or Y), respectively, In addition, the frequency of diploidy (X-Y-8-8) was 18.6 and auto-diploidies (X-X-8-8 and Y-Y-8-8) were 1.0 and 2.0, respectively. These frequencies were not significantly different when compared with levels in healthy men (p > 0.1). Our finding suggests that chromosome X, Y and 8 aneuploidies are not elevated in the sperm of A-T patients, but studies with additional patients and chromosomes are needed.

  19. Ataxia-Telangiectasia Mutated and the Mre11-Rad50-NBS1 Complex:Promising Targets for Radiosensitization

    Directory of Open Access Journals (Sweden)

    Kuroda,Shinji

    2012-04-01

    Full Text Available Radiotherapy plays a central part in cancer treatment, and use of radiosensitizing agents can greatly enhance this modality. Although studies have shown that several chemotherapeutic agents have the potential to increase the radiosensitivity of tumor cells, investigators have also studied a number of molecularly targeted agents as radiosensitizers in clinical trials based on reasonably promising preclinical data. Recent intense research into the DNA damage-signaling pathway revealed that ataxia-telangiectasia mutated (ATM and the Mre11-Rad50-NBS1 (MRN complex play central roles in DNA repair and cell cycle checkpoints and that these molecules are promising targets for radiosensitization. Researchers recently developed three ATM inhibitors (KU-55933, CGK733, and CP466722 and an MRN complex inhibitor (mirin and showed that they have great potential as radiosensitizers of tumors in preclinical studies. Additionally, we showed that a telomerase-dependent oncolytic adenovirus that we developed (OBP-301 [telomelysin] produces profound radiosensitizing effects by inhibiting the MRN complex via the adenoviral E1B55kDa protein. A recent Phase I trial in the United States determined that telomelysin was safe and well tolerated in humans, and this agent is about to be tested in combination with radiotherapy in a clinical trial based on intriguing preclinical data demonstrating that telomelysin and ionizing radiation can potentiate each other. In this review, we highlight the great potential of ATM and MRN complex inhibitors, including telomelysin, as radiosensitizing agents.

  20. A radiation hybrid map of human chromosome 11q22-q23 containing the ataxia-telangiectasia disease locus

    Energy Technology Data Exchange (ETDEWEB)

    Richard, C.W. III; Cox, D.R.; Kapp, L.; Murnane, J. (Univ. of California, San Francisco, CA (United States)); Cornelis, F.; Julier, C.; Lathrop, M.; James, M.R. (Centre d' Etude du Polymorphisme Humain, Paris (France))

    1993-07-01

    The authors describe a high-resolution radiation hybrid map of human chromosome 11q22-q23 containing the ataxia-telangiectasia (AT) disease gene loci. The order and intermarker distances of 32 chromosome 11q22-q23 markers were determined by a multipoint maximum likelihood method analysis of the cosegregation of markers in 100 radiation hybrids. The radiation hybrid map of polymorphic loci was consistent with genetic linkage maps of common markers. Several genes, including [alpha]B-crystallin, adrenal ferrodoxin, CBL2, collagenase, dopamine receptor type 2, neural cell adhesion molecule, progesterone receptor, and stromelysins 1 and 2, were placed in relation to previously ordered, genetically mapped polymorphic loci. Five new markers ([alpha]B-crystallin, adrenal ferrodoxin, CJ52.114, CJ52.3, and D11S535) were ordered within the current published flanking markers for the AT group A and group C disease loci. A candidate AT group D gene (ATDC) identified by Kapp et al. was mapped telomeric to THY1, outside the flanking markers identified by multipoint linkage analysis for the major AT locus. 29 refs., 1 fig., 2 tabs.

  1. Ataxia Telangiectasia

    Science.gov (United States)

    ... all related organizations Publications Ataxias and Cerebellar or Spinocerebellar Degeneration Information Page Ataxias and Cerebellar/Spinocerebellar Degeneration information sheet compiled by ...

  2. Bladder Wall Telangiectasia in a Patient with Ataxia-Telangiectasia and How to Manage?

    Directory of Open Access Journals (Sweden)

    Fatma Deniz Aygün

    2015-01-01

    Full Text Available Ataxia-telangiectasia (A-T is a rare neurodegenerative, inherited disease causing severe morbidity. Oculocutaneous telangiectasias are almost constant findings among the affected cases as telangiectasia is considered the main clinical finding for diagnosis. Vascular abnormalities in organs have been reported infrequently but bladder wall telangiectasias are extremely rare. We aimed to report recurrent hemorrhage from bladder wall telangiectasia in a 9-year-old boy with A-T who had received intravenous cyclophosphamide for non-Hodgkin’s lymphoma. Since A-T patients are known to be more susceptible to chemical agents, we suggested that possibly cyclophosphamide was the drug which induced bladder wall injury in this patient.

  3. Chemo- and radiosensitivity testing in a patient with ataxia telangiectasia and Hodgkin disease.

    Science.gov (United States)

    Tamminga, R Y J; Dolsma, W V; Leeuw, J A; Kampinga, H H

    2002-01-01

    Treatment of Hodgkin disease (HD) in ataxia telangiectasia (AT) patients is hampered by hypersensitivity to radiation and chemotherapy. Most patients die, due to toxicity or, rarely, to progressive disease. The authors report on a 9-year-old girl with stage IIA HD and AT She was treated with a tailored combined modality approach. No unacceptable toxicity was found, but the girl died of a relapse outside the irradiation field. In comparison with fibroblasts of non-AT patients, the fibroblasts of the patient were 3 times as sensitive for radiotherapy but just 1.2 times as sensitive for doxorubicin. A good correlation was shown between in vitro radio- and chemosensitivity testing and the observed clinical toxicity. The authors suggest, therefore, treating AT patients as much as possible according to standard protocols by adjusting the radiotherapy delivery and the chemotherapy regimen to individual doses derived from in vitro radio- and chemosensitivity testing.

  4. Oxidative stress, mitochondrial abnormalities and antioxidant defense in Ataxia-telangiectasia, Bloom syndrome and Nijmegen breakage syndrome

    Directory of Open Access Journals (Sweden)

    Mateusz Maciejczyk

    2017-04-01

    Full Text Available Rare pleiotropic genetic disorders, Ataxia-telangiectasia (A-T, Bloom syndrome (BS and Nijmegen breakage syndrome (NBS are characterised by immunodeficiency, extreme radiosensitivity, higher cancer susceptibility, premature aging, neurodegeneration and insulin resistance. Some of these functional abnormalities can be explained by aberrant DNA damage response and chromosomal instability. It has been suggested that one possible common denominator of these conditions could be chronic oxidative stress caused by endogenous ROS overproduction and impairment of mitochondrial homeostasis. Recent studies indicate new, alternative sources of oxidative stress in A-T, BS and NBS cells, including NADPH oxidase 4 (NOX4, oxidised low-density lipoprotein (ox-LDL or Poly (ADP-ribose polymerases (PARP. Mitochondrial abnormalities such as changes in the ultrastructure and function of mitochondria, excess mROS production as well as mitochondrial damage have also been reported in A-T, BS and NBS cells. A-T, BS and NBS cells are inextricably linked to high levels of reactive oxygen species (ROS, and thereby, chronic oxidative stress may be a major phenotypic hallmark in these diseases. Due to the presence of mitochondrial disturbances, A-T, BS and NBS may be considered mitochondrial diseases. Excess activity of antioxidant enzymes and an insufficient amount of low molecular weight antioxidants indicate new pharmacological strategies for patients suffering from the aforementioned diseases. However, at the current stage of research we are unable to ascertain if antioxidants and free radical scavengers can improve the condition or prolong the survival time of A-T, BS and NBS patients. Therefore, it is necessary to conduct experimental studies in a human model.

  5. Ataxia-telangiectasia: Linkage analysis in highly inbred Arab and Druze families and differentiation from an ataxia-microcephaly-cataract syndrome

    NARCIS (Netherlands)

    Y. Ziv (Yael); M. Frydman (Moshe); E.M. Lange (Ethan); N. Zelnik (N.); G. Rotman (Galit); C. Julier (C.); N.G.J. Jaspers (Nicolaas); E. Dagan (Efrat); D. Abeliovicz (Dvorah); H. Dar (H.); Z. Borochowitz (Z.); M. Lathrop (Mark); A. Gatti (Arianna); Y. Shiloh (Yosef)

    1992-01-01

    textabstractAtaxia-telangiectasia (A-T) is a progressive autosomal recessive disease featuring neurodegeneration, immunodeficiency, chromosomal instability, radiation sensitivity and a highly increased proneness to cancer. A-T is ethnically widespread and genetically heterogeneous, as indicated by t

  6. Deficiency of ataxia telangiectasia mutated kinase modulates cardiac remodeling following myocardial infarction: involvement in fibrosis and apoptosis.

    Directory of Open Access Journals (Sweden)

    Cerrone R Foster

    Full Text Available Ataxia telangiectasia mutated kinase (ATM is a cell cycle checkpoint protein activated in response to DNA damage. We recently reported that ATM plays a protective role in myocardial remodeling following β-adrenergic receptor stimulation. Here we investigated the role of ATM in cardiac remodeling using myocardial infarction (MI as a model.Left ventricular (LV structure, function, apoptosis, fibrosis, and protein levels of apoptosis- and fibrosis-related proteins were examined in wild-type (WT and ATM heterozygous knockout (hKO mice 7 days post-MI. Infarct sizes were similar in both MI groups. However, infarct thickness was higher in hKO-MI group. Two dimensional M-mode echocardiography revealed decreased percent fractional shortening (%FS and ejection fraction (EF in both MI groups when compared to their respective sham groups. However, the decrease in %FS and EF was significantly greater in WT-MI vs hKO-MI. LV end systolic and diastolic diameters were greater in WT-MI vs hKO-MI. Fibrosis, apoptosis, and α-smooth muscle actin staining was significantly higher in hKO-MI vs WT-MI. MMP-2 protein levels and activity were increased to a similar extent in the infarct regions of both groups. MMP-9 protein levels were increased in the non-infarct region of WT-MI vs WT-sham. MMP-9 protein levels and activity were significantly lower in the infarct region of WT vs hKO. TIMP-2 protein levels similarly increased in both MI groups, whereas TIMP-4 protein levels were significantly lower in the infarct region of hKO group. Phosphorylation of p53 protein was higher, while protein levels of manganese superoxide dismutase were significantly lower in the infarct region of hKO vs WT. In vitro, inhibition of ATM using KU-55933 increased oxidative stress and apoptosis in cardiac myocytes.

  7. NAD(+) Replenishment Improves Lifespan and Healthspan in Ataxia Telangiectasia Models via Mitophagy and DNA Repair.

    Science.gov (United States)

    Fang, Evandro Fei; Kassahun, Henok; Croteau, Deborah L; Scheibye-Knudsen, Morten; Marosi, Krisztina; Lu, Huiming; Shamanna, Raghavendra A; Kalyanasundaram, Sumana; Bollineni, Ravi Chand; Wilson, Mark A; Iser, Wendy B; Wollman, Bradley N; Morevati, Marya; Li, Jun; Kerr, Jesse S; Lu, Qiping; Waltz, Tyler B; Tian, Jane; Sinclair, David A; Mattson, Mark P; Nilsen, Hilde; Bohr, Vilhelm A

    2016-10-11

    Ataxia telangiectasia (A-T) is a rare autosomal recessive disease characterized by progressive neurodegeneration and cerebellar ataxia. A-T is causally linked to defects in ATM, a master regulator of the response to and repair of DNA double-strand breaks. The molecular basis of cerebellar atrophy and neurodegeneration in A-T patients is unclear. Here we report and examine the significance of increased PARylation, low NAD(+), and mitochondrial dysfunction in ATM-deficient neurons, mice, and worms. Treatments that replenish intracellular NAD(+) reduce the severity of A-T neuropathology, normalize neuromuscular function, delay memory loss, and extend lifespan in both animal models. Mechanistically, treatments that increase intracellular NAD(+) also stimulate neuronal DNA repair and improve mitochondrial quality via mitophagy. This work links two major theories on aging, DNA damage accumulation, and mitochondrial dysfunction through nuclear DNA damage-induced nuclear-mitochondrial signaling, and demonstrates that they are important pathophysiological determinants in premature aging of A-T, pointing to therapeutic interventions.

  8. Concordance of ATM (ataxia telangiectasia mutated) immunohistochemistry between biopsy or metastatic tumor samples and primary tumors in gastric cancer patients.

    Science.gov (United States)

    Kim, Hee Sung; Kim, Min A; Hodgson, Darren; Harbron, Christopher; Wellings, Robert; O'Connor, Mark J; Womack, Christopher; Yin, Xiaolu; Bang, Yung-Jue; Im, Seok-Ah; Lee, Byung Lan; Kim, Woo Ho

    2013-01-01

    ATM (ataxia telangiectasia mutated) is one of several DNA repair proteins that are suggested to sensitize tumor cells to the poly(ADP-ribose) polymerase inhibitor olaparib when deficient. The aim of this study was to assess the spatiotemporal concordance of ATM immunohistochemistry (IHC) in gastric cancer in order to determine if measurements made at the level of various sample types and times could be inferred as having the potential to be relevant to treatment decisions made at the patient level. Two independent cohorts composed of 591 gastric cancer patients divided into a gastrectomy cohort (n = 450) and a metastasis cohort (n = 141) were used in this study. A total of 2,705 ATM IHC samples were examined, including 450 whole tissue, 3 sets of 450 tissue microarray (TMA), 301 biopsy, 222 metastatic tumor and 2 additional whole tissue samples of 50 cases from the gastrectomy cohort, and 141 pairs of primary and metastatic tumors from the metastasis cohort. The prevalence of ATM negativity was 13.1% in biopsies, 13.9, 15.1, and 16.0% in TMAs and 15.9% in whole tissue samples of the gastrectomy cohort, and 21.4% in primary tumor and 21.5% in metastatic tumor samples of the metastasis cohort. coefficients were 0.341 for biopsy, 0.572 as the average of 3 TMAs and 0.415 for the largely synchronous metastatic tumors of the gastrectomy cohort, and 0.153 for the largely asynchronous metastatic tumors of the metastasis cohort. Using whole tissue sections from tumor resections or primary tumor, respectively, as the reference standards, specificity and sensitivity were 91.6 and 41.0% for biopsy, 93.9 and 61.9% as the average of 3 TMAs, and 86.6 and 58.8% for metastatic tumors of the gastrectomy cohort and 81.7 and 33.3% for metastatic tumors of the metastasis cohort, respectively. Although we have demonstrated that the IHC assay for ATM was robust and reproducible in gastric tumor samples, we have also found that measurements were subject to significant discordance across

  9. Effects of 4-aminopyridine on nystagmus and vestibulo-ocular reflex in ataxia-telangiectasia.

    Science.gov (United States)

    Shaikh, Aasef G; Marti, Sarah; Tarnutzer, Alexander A; Palla, Antonella; Crawford, Thomas O; Zee, David S; Straumann, Dominik

    2013-11-01

    Ataxia-telangiectasia (A-T) is a progressive neurodegenerative disorder with prominent eye movement deficits localizing to the cerebellum. We sought to determine if 4-aminopyridine (4-AP), which putatively enhances the precision of Purkinje neurons, could improve the disorders of eye movements and vestibular function in A-T. The influence of 4-AP on disorders of eye movements and vestibular function was studied in four A-T patients. The effects on the cerebellar control of vestibulo-ocular reflex (VOR) was quantitatively assessed by the decay time constant of per- and post-rotational nystagmus during constant velocity en bloc rotations. The length of the VOR time constant determines the fidelity of the vestibular velocity storage, a neural mechanism that increases the bandwidth of VOR under cerebellar control. The VOR time constant was not increased in A-T patients. The latter is explained by the extent of cerebellar lesion as previously described in A-T and other cerebellar disorders. Nevertheless, 4-AP shortened the VOR time constant during horizontal rotations. Severe disinhibition of velocity storage in subjects with putatively profound cerebellar degeneration manifest periodic alternating nystagmus (PAN). Among two A-T subjects who manifested PAN, 4-AP reduced the peak slow phase velocity of the more severely affected individual and abrogated the PAN in the other. Two A-T subjects manifested horizontal and vertical spontaneous nystagmus (SN) in primary gaze, 4-AP reduced its slow phase velocity. We conclude that in subjects with A-T 4-AP has a prominent effect on the ocular motor and vestibular deficits that are ascribed to the loss of cerebellar Purkinje neurons.

  10. Ataxia-telangiectasia-mutated (ATM) and NBS1-dependent phosphorylation of Chk1 on Ser-317 in response to ionizing radiation

    DEFF Research Database (Denmark)

    Gatei, Magtouf; Sloper, Katie; Sørensen, Claus Storgaard

    2003-01-01

    In mammals, the ATM (ataxia-telangiectasia-mutated) and ATR (ATM and Rad3-related) protein kinases function as critical regulators of the cellular DNA damage response. The checkpoint functions of ATR and ATM are mediated, in part, by a pair of checkpoint effector kinases termed Chk1 and Chk2...

  11. Ataxia Telangiectasia-Mutated (ATM) kinase activity is regulated by ATP-driven conformational changes in the Mre11/Rad50/Nbs1 (MRN) complex

    NARCIS (Netherlands)

    J.-H. Lee (Ji-Hoon); M.R. Mand (Michael); R.A. Deshpande (Rajashree); E. Kinoshita (Eri); S.-H. Yang (Soo-Hyun); C. Wyman (Claire); T.T. Paull

    2013-01-01

    textabstractThe Ataxia Telangiectasia-Mutated (ATM) protein kinase is recruited to sites of double-strand DNA breaks by the Mre11/Rad50/Nbs1 (MRN) complex, which also facilitates ATM monomerization and activation. MRN exists in at least two distinct conformational states, dependent on ATP binding an

  12. Imaging study of lymphoreticular tumor development in ataxia-telangiectasia and Nijmegen breakage syndrome; Estudio por imagen del desarrollo de tumores linforreticulares en la ataxia telangiectasia y el sindrome de Nijmegen

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Leon, M. I.; Ceres-Ruiz, L.; Cuesta, M. A.; Garcia-Martin, F. J. [Hospital Materno-Infantil C.H.U. Carlos Haya. Malaga (Spain)

    2003-07-01

    Ataxia-telangiectasia (AT), or Louis-Bar syndrome, is an autosomal recessive illness characterized by progressive cerebellar ataxia, oculo-cutaneous telangiectasia, immunodeficiency combined with susceptibility to sinopulmonary infections and high incidence of neoplastic development. Nijmegen breakage syndrome (NBS) is a variant of AT, is also an autosomal recessive illness that presents cerebellar ataxia, as well as combined immunodeficiency and a tendency toward tumor development. Contrary to Louis-Bar syndrome, it doesn't present telangiectasia and exhibits a characteristics phenotype (short stature, bird-like face and microcephaly). Both entities are classified as syndrome of chromosomal instability or chromosomal fragility, a group which also includes Bloom syndrome and Fanconi anemia. All of these show an increase in the frequency of neoplastic pathologies, mainly lymphoid tumors. We present three patients,two with AT and one with NBS, who developed different lymphoma types in the course of the illness. We highlight the most outstanding aspects from a clinical-radiological point of view. (Author) 17 refs.

  13. Targeted Next-Generation Sequencing Revealed Novel Mutations in Chinese Ataxia Telangiectasia Patients: A Precision Medicine Perspective.

    Directory of Open Access Journals (Sweden)

    Zhao Chen

    Full Text Available Ataxia telangiectasia (AT is an autosomal recessive disease characterized by progressive cerebellar ataxia, oculocutaneous telangiectasia and immunodeficiency due to mutations in the ATM gene. We performed targeted next-generation sequencing (NGS on three unrelated patients and identified five disease-causing variants in three probands, including two pairs of heterozygous variants (FAT-1:c.4396C>T/p.R1466X, c.1608-2A>G; FAT-2:c.4412_4413insT/p.L1472Ffs*19, c.8824C>T/p.Q2942X and one pair of homozygous variants (FAT-3: c.8110T>G/p.C2704G, Hom. With regard to precision medicine for rare genetic diseases, targeted NGS currently enables the rapid and cost-effective identification of causative mutations and is an updated molecular diagnostic tool that merits further optimization. This high-throughput data-based strategy would propel the development of precision diagnostic methods and establish a foundation for precision medicine.

  14. Radio-induced apoptosis is impaired in individuals homozygous and heterozygous for the ataxia-telangiectasia gene(s); Alteration de la reponse apoptotique radio-induite chez des homozygotes et des heterozygotes pour l`ataxie-telangiectasie

    Energy Technology Data Exchange (ETDEWEB)

    Duchaud, E.; Ridet, A.; Delic, Y.; Moustacchi, E.; Rosselli, F. [Institut Curie, 75 - Paris (France); Cundari, E. [Consiglio Nazionale delle Ricerche, Rome (Italy)

    1994-11-01

    Ataxia-telangiectasia is a progressive recessive disease featuring neuro degeneration, immunodeficiency, chromosomal instability, radiation hypersensitivity and increased predisposition to cancer. Impaired induction of the tumor suppressor protein p53 after {gamma}-irradiation was recently reported. All together these characteristics may be compatible with an inability to correctly regulate the apoptotic pathway of cell death in this syndrome. We show here that lymphocyte cultures from AT patients are characterized by a 3 times more elevated spontaneous level of apoptotic cells compared to normal ones. In spite of this, 24 h after exposure to {gamma}-irradiation (5 to 10 Gy), AT lymphocytes show a dramatically reduced capacity to undergo apoptosis compared to normal cells. We obtained similar results on EBV-transformed lymphoblasts. Interestingly, lymphoblasts from obligate heterozygous for the AT mutation(s) show the same features as AT lymphoblasts, i.e. an elevated frequency of spontaneous and a reduced level of radio-induced apoptotic figures in comparison to normal cultured cells. In conclusion, we show here, for the first time, that mutation(s) in AT gene(s) results in an impaired ability to correctly regulate the apoptotic pathway of cell death. (author). 26 refs., 4 figs., 2 tabs.

  15. Activation of eNOS in endothelial cells exposed to ionizing radiation involves components of the DNA damage response pathway

    Energy Technology Data Exchange (ETDEWEB)

    Nagane, Masaki; Yasui, Hironobu; Sakai, Yuri; Yamamori, Tohru [Laboratory of Radiation Biology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan); Niwa, Koichi [Laboratory of Biochemistry, Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri 099-2493 (Japan); Hattori, Yuichi [Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan); Kondo, Takashi [Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan); Inanami, Osamu, E-mail: inanami@vetmed.hokudai.ac.jp [Laboratory of Radiation Biology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan)

    2015-01-02

    Highlights: • eNOS activity is increased in BAECs exposed to X-rays. • ATM is involved in this increased eNOS activity. • HSP90 modulates the radiation-induced activation of ATM and eNOS. - Abstract: In this study, the involvement of ataxia telangiectasia mutated (ATM) kinase and heat shock protein 90 (HSP90) in endothelial nitric oxide synthase (eNOS) activation was investigated in X-irradiated bovine aortic endothelial cells. The activity of nitric oxide synthase (NOS) and the phosphorylation of serine 1179 of eNOS (eNOS-Ser1179) were significantly increased in irradiated cells. The radiation-induced increases in NOS activity and eNOS-Ser1179 phosphorylation levels were significantly reduced by treatment with either an ATM inhibitor (Ku-60019) or an HSP90 inhibitor (geldanamycin). Geldanamycin was furthermore found to suppress the radiation-induced phosphorylation of ATM-Ser1181. Our results indicate that the radiation-induced eNOS activation in bovine aortic endothelial cells is regulated by ATM and HSP90.

  16. Functional significance for a heterogenous ribonucleoprotein A18 signature RNA motif in the 3'-untranslated region of ataxia telangiectasia mutated and Rad3-related (ATR) transcript.

    Science.gov (United States)

    Yang, Ruiqing; Zhan, Ming; Nalabothula, Narasimha Rao; Yang, Qingyuan; Indig, Fred E; Carrier, France

    2010-03-19

    The predominantly nuclear heterogenous ribonucleoprotein A18 (hnRNP A18) translocates to the cytosol in response to cellular stress and increases translation by specifically binding to the 3'-untranslated region (UTR) of several mRNA transcripts and the eukaryotic initiation factor 4G. Here, we identified a 51-nucleotide motif that is present 11.49 times more often in the 3'-UTR of hnRNP A18 mRNA targets than in the UniGene data base. This motif was identified by computational analysis of primary sequences and secondary structures of hnRNP A18 mRNA targets against the unaligned sequences. Band shift analyses indicate that the motif is sufficient to confer binding to hnRNP A18. A search of the entire UniGene data base indicates that the hnRNP A18 motif is also present in the 3'-UTR of the ataxia telangiectasia mutated and Rad3-related (ATR) mRNA. Validation of the predicted hnRNP A18 motif is provided by amplification of endogenous ATR transcript on polysomal fractions immunoprecipitated with hnRNP A18. Moreover, overexpression of hnRNP A18 results in increased ATR protein levels and increased phosphorylation of Chk1, a preferred ATR substrate, in response to UV radiation. In addition, our data indicate that inhibition of casein kinase II or GSK3beta significantly reduced hnRNP A18 cytosolic translocation in response to UV radiation. To our knowledge, this constitutes the first demonstration of a post-transcriptional regulatory mechanism for ATR activity. hnRNP A18 could thus become a new target to trigger ATR activity as back-up stress response mechanisms to functionally compensate for absent or defective responders.

  17. Evidence that the Nijmegen breakage syndrome protein, an early sensor of double-strand DNA breaks (DSB), is involved in HIV-1 post-integration repair by recruiting the ataxia telangiectasia-mutated kinase in a process similar to, but distinct from, cellular DSB repair.

    Science.gov (United States)

    Smith, Johanna A; Wang, Feng-Xiang; Zhang, Hui; Wu, Kou-Juey; Williams, Kevin Jon; Daniel, René

    2008-01-22

    Retroviral transduction involves integrase-dependent linkage of viral and host DNA that leaves an intermediate that requires post-integration repair (PIR). We and others proposed that PIR hijacks the host cell double-strand DNA break (DSB) repair pathways. Nevertheless, the geometry of retroviral DNA integration differs considerably from that of DSB repair and so the precise role of host-cell mechanisms in PIR remains unclear. In the current study, we found that the Nijmegen breakage syndrome 1 protein (NBS1), an early sensor of DSBs, associates with HIV-1 DNA, recruits the ataxia telangiectasia-mutated (ATM) kinase, promotes stable retroviral transduction, mediates efficient integration of viral DNA and blocks integrase-dependent apoptosis that can arise from unrepaired viral-host DNA linkages. Moreover, we demonstrate that the ATM kinase, recruited by NBS1, is itself required for efficient retroviral transduction. Surprisingly, recruitment of the ATR kinase, which in the context of DSB requires both NBS1 and ATM, proceeds independently of these two proteins. A model is proposed emphasizing similarities and differences between PIR and DSB repair. Differences between the pathways may eventually allow strategies to block PIR while still allowing DSB repair.

  18. Ataxia telangiectasia-mutated-Rad3-related DNA damage checkpoint signaling pathway triggered by hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Fan Zhao; Qing-Jun Ma; Hui Zhong; Ning-Bo Hou; Xiao-Li Yang; Xiang He; Yu Liu; Yan-Hong Zhang; Cong-Wen Wei; Ting Song; Li Li

    2008-01-01

    AIM: To explore whether acute cellular DNA damage response is induced upon hepatitis B virus (HBV) infection and the effects of the HBV infection. METHODS: We incubated HL7702 hepatocytes with HBV-positive serum, mimicking a natural HBV infection process. We used immunoblotting to evaluate protein expression levels in HBV-infected cells or in non-infected cells; immunofluorescence to show ATR foci ands Chk1 phosphorylation loci formation; flow cytometry to analyze the cell cycle and apoptosis; ultraviolet (UV) radiation and ionizing radiation (IR)-treated cells to mimic DNA damage; and Trypan blue staining to count the viable cells.RESULTS: We found that HBV infection induced an increased steady state of ATR protein and increased phosphorylation of multiple downstream targets including Chkl, p53 and H2AX. In contrast to ATR and its target, the phosphorylated form of ATM at Ser-1981 and its downstream substrate Chk2 phosphorylation at Thr-68 did not visibly increase upon infection. However, the level of Mre11 and p21 were reduced beginning at 0.5 h after HBV-positive serum addition. Also, HBV infection led to transient cell cycle arrest in the S and the G2 phases without accompanying increased apoptosis. Research on cell survival changes upon radiation following HBV infection showed that survival of UV-treated host cells was greatly increased by HBV infection, owing to the reduced apoptosis. Meanwhile, survival of IR-treated host cells was reduced by HBV infection. CONCLUSION: HBV infection activates ATR DNA damage response to replication stress and abrogates the checkpoint signaling controlled by DNA damage response.

  19. Ataxia-telangiectasia: an overview.

    Science.gov (United States)

    Boder, E

    1985-01-01

    The more subtle clinical findings that facilitate early diagnosis and the most provocative long-term clinical observations in our series of patients are emphasized. The most striking pathological findings in our own series of 11 complete autopsies are reviewed in relation to new findings from 57 autopsy reports in the recent literature. Clinical and pathological findings in our oldest patient, who died at age 32, are systematically compared with those of her sister, who died 20 years earlier at age 10 1/2 and who was the subject of the first autopsy in AT, thus providing a rare comparison of the early and late stages of the disease. The clinical and pathological findings, including the gliovascular malformations in the CNS described recently in autopsies on older patients, reveal that AT is characterized throughout its course by multisystemic progeric changes. It is proposed, therefore, that AT can serve as a model for the study of premature aging. Clinical diagnosis, laboratory markers, and special diagnostic procedures, along with general management, immunotherapy, and rehabilitative measures, are reviewed in Part II.

  20. Regulation of ATM in DNA double strand break repair accounts for the radiosensitivity in human cells exposed to high linear energy transfer ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Xue Lian, E-mail: xuelian@suda.edu.cn [School of Radiation Medicine and Public Health, Medical College of Soochow University, No. 199, Ren' ai Road, Suzhou 215123 (China); Yu Dong, E-mail: ydong@ncc.go.jp [Tumor Endocrinology Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Furusawa, Yoshiya; Okayasu, Ryuichi [Heavy-Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan); Tong Jian; Cao Jianping; Fan Saijun [School of Radiation Medicine and Public Health, Medical College of Soochow University, No. 199, Ren' ai Road, Suzhou 215123 (China)

    2009-11-02

    High linear energy transfer (LET) radiation shows different biological effects from low-LET radiation. The complex nature of high LET radiation-induced damage, especially the clustered DNA damage, brings about slow repair of DNA double strand breaks (DSBs), which finally lead to higher lethality and chromosome aberration. Ionizing radiation (IR) induced DNA DSBs are repaired by both non-homologous end-joining (NHEJ) and homologous recombination repair (HRR) pathways in mammalian cells. The novel function of ataxia telangiectasia-mutated (ATM) protein is its involvement in the DSB repair of slow kinetics for 'dirty' breaks rejoining by NHEJ, this suggests that ATM may play a more important role in high LET radiation-induced DNA damage. We show here that KU55933, an ATM inhibitor could distinctly lower the clonogenic survival in normal human skin fibroblast cells exposed to carbon ion radiation and dramatically impair the normal process for DSB repair. We also implicated the involvement of ATM in the two pathways of DNA DSB repair, with DNA-PKcs and Rad51 as the representative proteins. The phosphorylation of DNA-PKcs at Thr-2609 with both immunoblotting and immunofluorescent staining indicated an ATM-dependent change, while for Rad51, KU55933 pretreatment could postpone the formation of nuclear Rad51 foci. Interestingly, we also found that pretreatment with chloroquine, an ATM stimulator could protect cells from carbon ion radiation only at lower doses. For doses over 1 Gy, protection was no longer observed. There was a dose-dependent increase for ATM kinase activity, with saturation at about 1 Gy. Chloroquine pretreatment prior to 1 Gy of carbon ion radiation did not enhance the autophosphorylation of ATM at serine 1981. The function of ATM in G2/M checkpoint arrest facilitated DSB repair in high-LET irradiation. Our results provide a possible mechanism for the direct involvement of ATM in DSB repair by high-LET irradiation.

  1. Cell division in the CNS: Protective response or lethal event in post-mitotic neurons?

    OpenAIRE

    Yang, Yan; Herrup, Karl

    2007-01-01

    Cell cycle events have been documented to be associated with several human neurodegenerative diseases. This review focuses on two diseases - Alzheimer’s disease and ataxia telangiectasia - as well as their mouse models. Cell cycle studies have shown that ectopic expression of cell cycle markers is spatially and regional correlated well with neuronal cell death in both disease conditions. Further evidence of ectopic cell cycling is found in both human diseases and in its mouse models. These fi...

  2. Methods for detection of ataxia telangiectasia mutations

    Energy Technology Data Exchange (ETDEWEB)

    Gatti, Richard A.

    2005-10-04

    The present invention is directed to a method of screening large, complex, polyexonic eukaryotic genes such as the ATM gene for mutations and polymorphisms by an improved version of single strand conformation polymorphism (SSCP) electrophoresis that allows electrophoresis of two or three amplified segments in a single lane. The present invention also is directed to new mutations and polymorphisms in the ATM gene that are useful in performing more accurate screening of human DNA samples for mutations and in distinguishing mutations from polymorphisms, thereby improving the efficiency of automated screening methods.

  3. Ataxia-telangiectasia. (Clinical and immunological aspects).

    Science.gov (United States)

    Boder, E; Sedgwick, R P

    1970-01-01

    This syndrome was defined by the authors in 1947. Earlier publications of similar disease descriptions were by Syllaba and Henner (1926), Louis-Bar (1941). The authors at present have a stock of 253 cases. The cardinal symptoms of this phakomatosis are: Cerebellar ataxia which begin in infancy and take a slowly progressive course. In the late stages free walking and standing are no longer possible. Progressive atactic speech disorders, cerebellar atrophy in the pneumoencephalogram. Slowly progressing symmetrical skin and mucosal telangiectasia in the face and especially on the conjunctivae at the age of 3 to 6 years. Relapsing sinopulmonary infections with a tendency toward the development of bronchiectases. Apraxia of eye movements. Atrophy of facial skin and premature graying of hair. Recessively hereditary disorder with a high familial manifestation. This syndrome combines the spinocerebellar degeneration, phakomatoses, and infantile dementia processes. Such other conditions as abnormity or absence of thymus, reduction in gamma globulins, amino-aciduria, autosomal-recessive inheritance suggest a genetically determined "error of metabolism".

  4. Multiple Defects of Cell Cycle Checkpoints in U937-ASPI3K, an U937 Cell Mutant Stably Expressing Anti-Sense ATM Gene cDNA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    (Ataxia-telangiectasia mutated gene (ATM) functions in control of cell cycle checkpoints in responding to DNA damage and protects cells from undergoing apoptosis. Knock-out within tumor cells of endogenous ATM will achieve therapeutic benefits and nable a better understanding of the decisive mechanisms of cell death or survival in response to DNA damaging agents. ) In present paper, we sought to characterize the cell cycle checkpoint profiles in U937-ASPI3K, a U937 cell mutant that was previously established with endogenous ATM knock-out phenotype. Synchronized U937-ASPI3K was exposed to 137Cs irradiation, G1, S, G2/M cell cycle checkpoint profiles were evaluated by determining cell cycle kinetics, p53/p21 protein, cyclin dependent kinase 2 (CDK2) and p34CDC2 kinase activity in response to irradiation. U937-ASPI3K exhibited multiple defects in cell cycle checkpoints as defined by failing to arrest cells upon irradiation. The accumulation of cellular p53/p21 protein and inhibition of CDK kinase was also abolished in U937-ASPI3K. It was concluded that the stable expression of anti-sense PI3K cDNA fragment completely abolished multiple cell cycle checkpoints in U937-ASPI3K, and hence U937-ASPI3K with an AT-like phenotype could serves as a valuable model system for investigating the signal transduction pathway in responding to DNA damaging-based cancer therapy.

  5. Methacryloxylethyl Cetyl Ammonium Chloride Induces DNA Damage and Apoptosis in Human Dental Pulp Cells via Generation of Oxidative Stress.

    Science.gov (United States)

    Jiao, Yang; Ma, Sai; Wang, Yirong; Li, Jing; Shan, Lequn; Sun, Jinlong; Chen, Jihua

    2016-01-01

    The polymerizable antibacterial monomer methacryloxylethyl cetyl ammonium chloride (DMAE-CB) has provided an effective strategy to combat dental caries. However, the application of such material raises the question about the biological safety and the question remains open. The mechanism of this toxic action, however, is not yet clearly understood. The present study aims at providing novel insight into the possible causal link between cellular oxidative stress and DNA damage, as well as apoptosis in human dental pulp cells exposed to DMAE-CB. The enhanced formation of reactive oxygen species and depletion of glutathione, as well as differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase in DMAE-CB-treated cells indicated oxidative stress. By using substances that can alter GSH synthesis, we found that GSH was the key component in the regulation of cell response towards oxidative stress induced by DMAE-CB. The increase in oxidative stress-sensitive 8-Oxo-2'-deoxyguanosine (8-OHdG) content, formation of γ-H2AX and cell cycle G1 phase arrest indicated that DNA damage occurred as a result of the interaction between DNA base and ROS beyond the capacities of antioxidant mechanisms in cells exposed to DMAE-CB. Such oxidative DNA damage thus triggers the activation of ataxia telangiectasia-mutated (ATM) signaling, the intrinsic apoptotic pathway, and destruction of mitochondrial morphology and function.

  6. Deficient recovery from potentially lethal damage in some gamma-irradiated human fibroblast cell strains

    Energy Technology Data Exchange (ETDEWEB)

    Arlett, C.F.; Priestley, A. (Medical Research Council, Brighton (UK). Cell Mutation Unit)

    1984-01-01

    The repair of potentially lethal damage following treatment with gamma radiation was investigated in human fibroblasts held in a non-cycling state by maintenance in a medium containing 0.5% foetal calf serum. Normal cells were found to be competent in the repair of PLD. Ataxia-telangiectasia cells were deficient as was a heterozygote suggesting that a failure to repair PLD may make it possible to detect such heterozygotes. Fibroblasts from Huntington's disease patients were either slightly or no more sensitive than cells from normal individuals. Cultures from two individuals in the former class showed limited capacity to repair PLD but cells from the latter class were as competent as normals. Thus assays of radiosensitivity where conditions allow for the repair of PLD may maximise small differences in sensitivity. Cells taken from three patients suffering from Basal Cell Naevus Syndrome were also shown to be defective in the repair of PLD. The existence of such a defect may be related to the increased frequency of basal cell cancer observed in exposed fields following irradiation of such individuals.

  7. Breast cancer stem cell-like cells are more sensitive to ionizing radiation than non-stem cells: role of ATM.

    Directory of Open Access Journals (Sweden)

    Seog-Young Kim

    Full Text Available There are contradictory observations about the different radiosensitivities of cancer stem cells and cancer non-stem cells. To resolve these contradictory observations, we studied radiosensitivities by employing breast cancer stem cell (CSC-like MDA-MB231 and MDA-MB453 cells as well as their corresponding non-stem cells. CSC-like cells proliferate without differentiating and have characteristics of tumor-initiating cells [1]. These cells were exposed to γ-rays (1.25-8.75 Gy and survival curves were determined by colony formation. A final slope, D(0, of the survival curve for each cell line was determined to measure radiosensitivity. The D(0 of CSC-like and non-stem MDA-MB-453 cells were 1.16 Gy and 1.55 Gy, respectively. Similar results were observed in MDA-MB-231 cells (0.94 Gy vs. 1.56 Gy. After determination of radiosensitivity, we investigated intrinsic cellular determinants which influence radiosensitivity including cell cycle distribution, free-radical scavengers and DNA repair. We observed that even though cell cycle status and antioxidant content may contribute to differential radiosensitivity, differential DNA repair capacity may be a greater determinant of radiosensitivity. Unlike non-stem cells, CSC-like cells have little/no sublethal damage repair, a low intracellular level of ataxia telangiectasia mutated (ATM and delay of γ-H2AX foci removal (DNA strand break repair. These results suggest that low DNA repair capacity is responsible for the high radiosensitivity of these CSC-like cells.

  8. MicroRNA-22 promotes cell survival upon UV radiation by repressing PTEN

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Guangyun [Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis, TN (United States); Center for Adult Cancer Research, University of Tennessee Health Science Center, Memphis, TN (United States); Jilin Province Key Laboratory of Animal Embryo Engineering, Jilin University, Changchun (China); Shi, Yuling [Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis, TN (United States); Center for Adult Cancer Research, University of Tennessee Health Science Center, Memphis, TN (United States); Wu, Zhao-Hui, E-mail: zwu6@uthsc.edu [Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis, TN (United States); Center for Adult Cancer Research, University of Tennessee Health Science Center, Memphis, TN (United States)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer miR-22 is induced in cells treated with UV radiation. Black-Right-Pointing-Pointer ATM is required for miR-22 induction in response to UV. Black-Right-Pointing-Pointer miR-22 targets 3 Prime -UTR of PTEN to repress its expression in UV-treated cells. Black-Right-Pointing-Pointer Upregulated miR-22 inhibits apoptosis in cells exposed to UV. -- Abstract: DNA damage response upon UV radiation involves a complex network of cellular events required for maintaining the homeostasis and restoring genomic stability of the cells. As a new class of players involved in DNA damage response, the regulation and function of microRNAs in response to UV remain poorly understood. Here we show that UV radiation induces a significant increase of miR-22 expression, which appears to be dependent on the activation of DNA damage responding kinase ATM (ataxia telangiectasia mutated). Increased miR-22 expression may result from enhanced miR-22 maturation in cells exposed to UV. We further found that tumor suppressor gene phosphatase and tensin homolog (PTEN) expression was inversely correlated with miR-22 induction and UV-induced PTEN repression was attenuated by overexpression of a miR-22 inhibitor. Moreover, increased miR-22 expression significantly inhibited the activation of caspase signaling cascade, leading to enhanced cell survival upon UV radiation. Collectively, these results indicate that miR-22 is an important player in the cellular stress response upon UV radiation, which may promote cell survival via the repression of PTEN expression.

  9. Survey of radiosensitivity in a variety of human cell strains

    Energy Technology Data Exchange (ETDEWEB)

    Arlett, C.F.; Harcourt, S.A.

    1980-03-01

    Gamma-ray sensitivity for cell killing was assayed in 54 human cell strains, including some derived from individuals suffering from certain hereditary diseases. The overall range of Do values in this study was 38 to 180 rads, indicating a considerable range of variability in humans. The normal sensitivity was described by a range of Do values of 97 to 180 rads. All ten ataxia telangiectasia cell strains tested proved radiosensitive and gave a mean Do value of 57 +- 15 (S.E.) rads, and these represent the most radiosensitive human skin fibroblasts currently available. Representative cell strains from familial retinoblastoma, Fanconi's anemia, and Hutchinson-Gilford progeria occupied positions of intermediate sensitivity, as did one of two ataxia telangiectasia heterozygotes. Six xeroderma pigmentosum cell strains together with two Cockayne's syndrome cell strains (all known to be sensitive to ultraviolet light) fell into the normal range, indicating an absence of cross-sensitivity between ultraviolet light and gamma-irradiation.

  10. Gene for ataxia-telangiectasia complementation group D (ATDC)

    Energy Technology Data Exchange (ETDEWEB)

    Murnane, John P. (San Francisco, CA); Painter, Robert B. (Burlingame, CA); Kapp, Leon N. (San Rafael, CA); Yu, Loh-Chung (Redwood City, CA)

    1995-03-07

    Disclosed herein is a new gene, an AT gene for complementation group D, the ATDC gene and fragments thereof. Nucleic acid probes for said gene are provided as well as proteins encoded by said gene, cDNA therefrom, preferably a 3 kilobase (kb) cDNA, and recombinant nucleic acid molecules for expression of said proteins. Further disclosed are methods to detect mutations in said gene, preferably methods employing the polymerase chain reaction (PCR). Also disclosed are methods to detect AT genes from other AT complementation groups.

  11. Gene for ataxia-telangiectasia complementation group D (ATDC)

    Energy Technology Data Exchange (ETDEWEB)

    Murnane, J.P.; Painter, R.B.; Kapp, L.N.; Yu, L.C.

    1995-03-07

    Disclosed herein is a new gene, an AT gene for complementation group D, the ATDC gene and fragments thereof. Nucleic acid probes for the gene are provided as well as proteins encoded by the gene, cDNA therefrom, preferably a 3 kilobase (kb) cDNA, and recombinant nucleic acid molecules for expression of the proteins. Further disclosed are methods to detect mutations in the gene, preferably methods employing the polymerase chain reaction (PCR). Also disclosed are methods to detect AT genes from other AT complementation groups. 30 figs.

  12. Gypenosides causes DNA damage and inhibits expression of DNA repair genes of human oral cancer SAS cells.

    Science.gov (United States)

    Lu, Kung-Wen; Chen, Jung-Chou; Lai, Tung-Yuan; Yang, Jai-Sing; Weng, Shu-Wen; Ma, Yi-Shih; Tang, Nou-Ying; Lu, Pei-Jung; Weng, Jing-Ru; Chung, Jing-Gung

    2010-01-01

    Gypenosides (Gyp) are the major components of Gynostemma pentaphyllum Makino, a Chinese medical plant. Recently, Gyp has been shown to induce cell cycle arrest and apoptosis in many human cancer cell lines. However, there is no available information to address the effects of Gyp on DNA damage and DNA repair-associated gene expression in human oral cancer cells. Therefore, we investigated whether Gyp induced DNA damage and DNA repair gene expression in human oral cancer SAS cells. The results from flow cytometric assay indicated that Gyp-induced cytotoxic effects led to a decrease in the percentage of viable SAS cells. The results from comet assay revealed that the incubation of SAS cells with Gyp led to a longer DNA migration smear (comet tail) when compared with control and this effect was dose-dependent. The results from real-time PCR analysis indicated that treatment of SAS cells with 180 mug/ml of Gyp for 24 h led to a decrease in 14-3-3sigma, DNA-dependent serine/threonine protein kinase (DNAPK), p53, ataxia telangiectasia mutated (ATM), ataxia-telangiectasia and Rad3-related (ATR) and breast cancer gene 1 (BRCA1) mRNA expression. These observations may explain the cell death caused by Gyp in SAS cells. Taken together, Gyp induced DNA damage and inhibited DNA repair-associated gene expressions in human oral cancer SAS cells in vitro.

  13. Alteration in 5-hydroxymethylcytosine-mediated epigenetic regulation leads to Purkinje cell vulnerability in ATM deficiency.

    Science.gov (United States)

    Jiang, Dewei; Zhang, Ying; Hart, Ronald P; Chen, Jianmin; Herrup, Karl; Li, Jiali

    2015-12-01

    A long-standing mystery surrounding ataxia-telangiectasia is why it is mainly cerebellar neurons, Purkinje cells in particular, that appear vulnerable to ATM deficiency. Here we present data showing that 5-hydroxymethylcytosine (5hmC), a newly recognized epigenetic marker found at high levels in neurons, is substantially reduced in human ataxia-telangiectasia and Atm(-/-) mouse cerebellar Purkinje cells. We further show that TET1, an enzyme that converts 5-methylcytosine (5mC) to 5hmC, responds to DNA damage and manipulation of TET1 activity directly affects the DNA damage signalling and ATM-deficient neuronal cell cycle re-entry and death. Quantitative genome-wide analysis of 5hmC-containing sequences shows that in ATM deficiency there is a cerebellum- and Purkinje cell-specific shift in 5hmC enrichment in both regulatory elements and repeated sequences. Finally, we verify that TET1-mediated 5hmC production is linked to the degenerative process of Purkinje cells and behavioural deficits in Atm(-/-) mice. Taken together, the selective loss of 5hmC plays a critical role in driving Purkinje cell vulnerability in ATM deficiency.

  14. ATM-Deficient Colorectal Cancer Cells Are Sensitive to the PARP Inhibitor Olaparib.

    Science.gov (United States)

    Wang, Chen; Jette, Nicholas; Moussienko, Daniel; Bebb, D Gwyn; Lees-Miller, Susan P

    2017-02-06

    The ataxia telangiectasia mutated (ATM) protein kinase plays a central role in the cellular response to DNA damage. Loss or inactivation of both copies of the ATM gene (ATM) leads to ataxia telangiectasia, a devastating childhood condition characterized by neurodegeneration, immune deficiencies, and cancer predisposition. ATM is also absent in approximately 40% of mantle cell lymphomas (MCLs), and we previously showed that MCL cell lines with loss of ATM are sensitive to poly-ADP ribose polymerase (PARP) inhibitors. Next-generation sequencing of patient tumors has revealed that ATM is altered in many human cancers including colorectal, lung, prostate, and breast. Here, we show that the colorectal cancer cell line SK-CO-1 lacks detectable ATM protein expression and is sensitive to the PARP inhibitor olaparib. Similarly, HCT116 colorectal cancer cells with shRNA depletion of ATM are sensitive to olaparib, and depletion of p53 enhances this sensitivity. Moreover, HCT116 cells are sensitive to olaparib in combination with the ATM inhibitor KU55933, and sensitivity is enhanced by deletion of p53. Together our studies suggest that PARP inhibitors may have potential for treating colorectal cancer with ATM dysfunction and/or colorectal cancer with mutation of p53 when combined with an ATM kinase inhibitor.

  15. ATM prevents DSB formation by coordinating SSB repair and cell cycle progression.

    Science.gov (United States)

    Khoronenkova, Svetlana V; Dianov, Grigory L

    2015-03-31

    DNA single-strand breaks (SSBs) arise as a consequence of spontaneous DNA instability and are also formed as DNA repair intermediates. Their repair is critical because they otherwise terminate gene transcription and generate toxic DNA double-strand breaks (DSBs) on replication. To prevent the formation of DSBs, SSB repair must be completed before DNA replication. To accomplish this, cells should be able to detect unrepaired SSBs, and then delay cell cycle progression to allow more time for repair; however, to date there is no evidence supporting the coordination of SSB repair and replication in human cells. Here we report that ataxia-telangiectasia mutated kinase (ATM) plays a major role in restricting the replication of SSB-containing DNA and thus prevents DSB formation. We show that ATM is activated by SSBs and coordinates their repair with DNA replication. SSB-mediated ATM activation is followed by a G1 cell cycle delay that allows more time for repair and thus prevents the replication of damaged DNA and DSB accrual. These findings establish an unanticipated role for ATM in the signaling of DNA SSBs and provide important insight into the molecular defects leading to genetic instability in patients with ataxia-telangiectasia.

  16. A review of adaptive mechanisms in cell responses towards oxidative stress caused by dental resin monomers.

    Science.gov (United States)

    Krifka, Stephanie; Spagnuolo, Gianrico; Schmalz, Gottfried; Schweikl, Helmut

    2013-06-01

    of glutathione (GSH), which is the major non-enzymatic antioxidant. The causal relationship between vital cell functions like the regulation of cell survival or cell death in monomer-treated cell cultures and the availability of GSH will be highlighted. We will also consider the influence of monomer-induced oxidative stress on central signal transduction pathways including mitogen-activated protein kinases (MAPK) ERK1/2, p38, and JNK as well as the stress-activated transcription factors downstream Elk-1, ATF-2, ATF-3, and cJun. Finally, we address signaling pathways originating from monomer-induced DNA damage including the activation of ATM (ataxia-telangiectasia mutated), Chk2, p53, p21, and H2AX. The understanding of the mechanisms underlying adaptive cell responses will stimulate a constructive debate on the development of smart dental restorative materials which come into contact with oral tissues and effective strategies in dental therapy.

  17. Cell death by the quinoxaline dioxide DCQ in human colon cancer cells is enhanced under hypoxia and is independent of p53 and p21

    Directory of Open Access Journals (Sweden)

    Haddadin Makhluf J

    2010-11-01

    Full Text Available Abstract Introduction We have shown that the radio sensitizer DCQ enhances sensitivity of HCT116 human colon cancer cells to hypoxia. However, it is not known whether the p53 or p21 genes influence cellular response to DCQ. In this study, we used HCT116 that are either wildtype for p53 and p21, null for p53 or null for p21 to understand the role of these genes in DCQ toxicity. Methods HCT116 cells were exposed to DCQ and incubated under normoxia or hypoxia and the viability, colony forming ability, DNA damage and apoptotic responses of these cells was determined, in addition to the modulation of HIF-1α and of p53, p21, caspase-2, and of the ataxia telangiectasia mutated (ATM target PIDD-C. Results DCQ decreased colony forming ability and viability of all HCT116 cells to a greater extent under hypoxia than normoxia and the p21-/-cell line was most sensitive. Cells had different HIF-1α responses to hypoxia and/or drug treatment. In p53+/+, DCQ significantly inhibited the hypoxia-induced increases in HIF-1α protein, in contrast to the absence of a significant HIF-1α increase or modulation by DCQ in p21-/- cells. In p53-/- cells, 10 μM DCQ significantly reduced HIF-1α expression, especially under hypoxia, despite the constitutive expression of this protein in control cells. Higher DCQ doses induced PreG1-phase increase and apoptosis, however, lower doses caused mitotic catastrophe. In p53+/+ cells, apoptosis correlated with the increased expression of the pro-apoptotic caspase-2 and inhibition of the pro-survival protein PIDD-C. Exposure of p53+/+ cells to DCQ induced single strand breaks and triggered the activation of the nuclear kinase ATM by phosphorylation at Ser-1981 in all cell cycle phases. On the other hand, no drug toxicity to normal FHs74 Int human intestinal cell line was observed. Conclusions Collectively, our findings indicate that DCQ reduces the colony survival of HCT116 and induces apoptosis even in cells that are null for p53

  18. ATM regulation of IL-8 links oxidative stress to cancer cell migration and invasion.

    Science.gov (United States)

    Chen, Wei-Ta; Ebelt, Nancy D; Stracker, Travis H; Xhemalce, Blerta; Van Den Berg, Carla L; Miller, Kyle M

    2015-06-01

    Ataxia-telangiectasia mutated (ATM) protein kinase regulates the DNA damage response (DDR) and is associated with cancer suppression. Here we report a cancer-promoting role for ATM. ATM depletion in metastatic cancer cells reduced cell migration and invasion. Transcription analyses identified a gene network, including the chemokine IL-8, regulated by ATM. IL-8 expression required ATM and was regulated by oxidative stress. IL-8 was validated as an ATM target by its ability to rescue cell migration and invasion defects in ATM-depleted cells. Finally, ATM-depletion in human breast cancer cells reduced lung tumors in a mouse xenograft model and clinical data validated IL-8 in lung metastasis. These findings provide insights into how ATM activation by oxidative stress regulates IL-8 to sustain cell migration and invasion in cancer cells to promote metastatic potential. Thus, in addition to well-established roles in tumor suppression, these findings identify a role for ATM in tumor progression.

  19. Increased oxidative stress in AOA3 cells disturbs ATM-dependent DNA damage responses.

    Science.gov (United States)

    Kobayashi, Junya; Saito, Yuichiro; Okui, Michiyo; Miwa, Noriko; Komatsu, Kenshi

    2015-04-01

    Ataxia telangiectasia (AT) is caused by a mutation in the ataxia-telangiectasia-mutated (ATM) gene; the condition is associated with hyper-radiosensitivity, abnormal cell-cycle checkpoints, and genomic instability. AT patients also show cerebellar ataxia, possibly due to reactive oxygen species (ROS) sensitivity in neural cells. The ATM protein is a key regulator of the DNA damage response. Recently, several AT-like disorders have been reported. The genes responsible for them are predicted to encode proteins that interact with ATM in the DNA-damage response. Ataxia with oculomotor apraxia types 1-3 (AOA1, 2, and 3) result in a neurodegenerative and cellular phenotype similar to AT; however, the basis of this phenotypic similarity is unclear. Here, we show that the cells of AOA3 patients display aberrant ATM-dependent phosphorylation and apoptosis following γ-irradiation. The ATM-dependent response to H2O2 treatment was abrogated in AOA3 cells. Furthermore, AOA3 cells had reduced ATM activity. Our results suggest that the attenuated ATM-related response is caused by an increase in endogenous ROS in AOA3 cells. Pretreatment of cells with pyocyanin, which induces endogenous ROS production, abolished the ATM-dependent response. Moreover, AOA3 cells had decreased homologous recombination (HR) activity, and pyocyanin pretreatment reduced HR activity in HeLa cells. These results indicate that excess endogenous ROS represses the ATM-dependent cellular response and HR repair in AOA3 cells. Since the ATM-dependent cell-cycle checkpoint is an important block to carcinogenesis, such inactivation of ATM may lead to tumorigenesis as well as neurodegeneration.

  20. Interferon-β-armed oncolytic adenovirus induces both apoptosis and necroptosis in cancer cells

    Institute of Scientific and Technical Information of China (English)

    Hongling Huang; Tian Xiao; Lingfeng He; Hongbin Ji; Xin-Yuan Liu

    2012-01-01

    Interferon-β (IFN-β) has been widely used in cancer therapy,but the clinical trial results are generally disappointing.Our previous studies have shown that an oncolytic adenovirus carrying IFN-β (ZD55-IFN-β) exhibits significant anti-tumor activities.However,the underlying mechanisms are not clear.Here we showed that ZD55-IFN-β infection-induced S-phase cell cycle arrest in a p53-dependent manner by activating the ataxia telangiectasia mutated-dependent DNA damage pathway.In addition, ZD55-IFN-β infection could initiate both caspase-dependent apoptosis and necroptosis in cancer cells.More importantly,ZD55-IFN-β showed a synergistic effect on cancer cells when combined with doxorubicin.These results suggest that the combination of ZD55-IFN-β with doxorubicin may represent a promising clinical strategy in cancer therapy.

  1. ATR inhibition induces synthetic lethality and overcomes chemoresistance in TP53- or ATM-defective chronic lymphocytic leukemia cells.

    Science.gov (United States)

    Kwok, Marwan; Davies, Nicholas; Agathanggelou, Angelo; Smith, Edward; Oldreive, Ceri; Petermann, Eva; Stewart, Grant; Brown, Jeff; Lau, Alan; Pratt, Guy; Parry, Helen; Taylor, Malcolm; Moss, Paul; Hillmen, Peter; Stankovic, Tatjana

    2016-02-04

    TP53 and ataxia telangiectasia mutated (ATM) defects are associated with genomic instability, clonal evolution, and chemoresistance in chronic lymphocytic leukemia (CLL). Currently, therapies capable of providing durable remissions in relapsed/refractory TP53- or ATM-defective CLL are lacking. Ataxia telangiectasia and Rad3-related (ATR) mediates response to replication stress, the absence of which leads to collapse of stalled replication forks into chromatid fragments that require resolution through the ATM/p53 pathway. Here, using AZD6738, a novel ATR kinase inhibitor, we investigated ATR inhibition as a synthetically lethal strategy to target CLL cells with TP53 or ATM defects. Irrespective of TP53 or ATM status, induction of CLL cell proliferation upregulated ATR protein, which then became activated in response to replication stress. In TP53- or ATM-defective CLL cells, inhibition of ATR signaling by AZD6738 led to an accumulation of unrepaired DNA damage, which was carried through into mitosis because of defective cell cycle checkpoints, resulting in cell death by mitotic catastrophe. Consequently, AZD6738 was selectively cytotoxic to both TP53- and ATM-defective CLL cell lines and primary cells. This was confirmed in vivo using primary xenograft models of TP53- or ATM-defective CLL, where treatment with AZD6738 resulted in decreased tumor load and reduction in the proportion of CLL cells with such defects. Moreover, AZD6738 sensitized TP53- or ATM-defective primary CLL cells to chemotherapy and ibrutinib. Our findings suggest that ATR is a promising therapeutic target for TP53- or ATM-defective CLL that warrants clinical investigation.

  2. ATM facilitates mouse gammaherpesvirus reactivation from myeloid cells during chronic infection.

    Science.gov (United States)

    Kulinski, Joseph M; Darrah, Eric J; Broniowska, Katarzyna A; Mboko, Wadzanai P; Mounce, Bryan C; Malherbe, Laurent P; Corbett, John A; Gauld, Stephen B; Tarakanova, Vera L

    2015-09-01

    Gammaherpesviruses are cancer-associated pathogens that establish life-long infection in most adults. Insufficiency of Ataxia-Telangiectasia mutated (ATM) kinase leads to a poor control of chronic gammaherpesvirus infection via an unknown mechanism that likely involves a suboptimal antiviral response. In contrast to the phenotype in the intact host, ATM facilitates gammaherpesvirus reactivation and replication in vitro. We hypothesized that ATM mediates both pro- and antiviral activities to regulate chronic gammaherpesvirus infection in an immunocompetent host. To test the proposed proviral activity of ATM in vivo, we generated mice with ATM deficiency limited to myeloid cells. Myeloid-specific ATM deficiency attenuated gammaherpesvirus infection during the establishment of viral latency. The results of our study uncover a proviral role of ATM in the context of gammaherpesvirus infection in vivo and support a model where ATM combines pro- and antiviral functions to facilitate both gammaherpesvirus-specific T cell immune response and viral reactivation in vivo.

  3. Depletion of hCINAP by RNA interference causes defects in Cajal body formation, histone transcription, and cell viability.

    Science.gov (United States)

    Zhang, Jinfang; Zhang, Feiyun; Zheng, Xiaofeng

    2010-06-01

    hCINAP is a highly conserved and ubiquitously expressed protein in eukaryotic organisms and its overexpression decreases the average number of Cajal bodies (CBs) with diverse nuclear functions. Here, we report that hCINAP is associated with important components of CBs. Depletion of hCINAP by RNA interference causes defects in CB formation and disrupts subcellular localizations of its components including coilin, survival motor neurons protein, spliceosomal small nuclear ribonucleoproteins, and nuclear protein ataxia-telangiectasia. Moreover, knockdown of hCINAP expression results in marked reduction of histone transcription, lower levels of U small nuclear RNAs (U1, U2, U4, and U5), and a loss of cell viability. Detection of increased caspase-3 activities in hCINAP-depleted cells indicate that apoptosis is one of the reasons for the loss of viability. Altogether, these data suggest that hCINAP is essential for the formation of canonical CBs, histone transcription, and cell viability.

  4. In-vivo assessment of DNA ligation efficiency and fidelity in cells from patients with Fanconi's anemia and other cancer-prone hereditary disorders.

    Science.gov (United States)

    Rünger, T M; Sobotta, P; Dekant, B; Möller, K; Bauer, C; Kraemer, K H

    1993-04-01

    We developed a host cell DNA ligation assay, in which we transfected linearized plasmid pZ189 into human lymphoblasts or fibroblasts in order to assess the efficiency and accuracy of DNA ligation within these host cells. We used cell lines from patients with Fanconi's anemia and other chromosome breakage or instability syndromes (Bloom's syndrome, ataxia telangiectasia, Werner's syndrome). With the Fanconi's anemia lymphoblast line GM8010 we did not find a reduced, but a slightly hypermutable DNA ligation. Mutation analysis revealed a unique 7.9-12.5-fold increase in insertions or complex mutations. With cells from the other chromosome breakage/instability syndromes we also found a hypermutable and/or reduced DNA ligation. An impaired DNA ligation might be a common molecular mechanism of genetic instability in these disorders.

  5. Unleashing Cancer Cells on Surfaces Exposing Motogenic IGDQ Peptides.

    Science.gov (United States)

    Corvaglia, Valentina; Marega, Riccardo; De Leo, Federica; Michiels, Carine; Bonifazi, Davide

    2016-01-20

    Thiolated peptides bearing the Ile-Gly-Asp (IGD) motif, a highly conserved sequence of fibronectin, are used for the preparation of anisotropic self-assembled monolayers (SAM gradients) to study the whole-population migratory behavior of metastatic breast cancer cells (MDA-MB-231 cells). Ile-Gly-Asp-Gln-(IGDQ)-exposing SAMs sustain the adhesion of MDA-MB-231 cells by triggering focal adhesion kinase phosphorylation, similarly to the analogous Gly-Arg-Gly-Asp-(GRGD)-terminating surfaces. However, the biological responses of different cell lines interfaced with the SAM gradients show that only those exposing the IGDQ sequence induce significant migration of MDA-MB-231 cells. In particular, the observed migratory behavior suggests the presence of cell subpopulations associated with a "stationary" or a "migratory" phenotype, the latter determining a considerable cell migration at the sub-cm length scale. These findings are of great importance as they suggest for the first time an active role of biological surfaces exposing the IGD motif in the multicomponent orchestration of cellular signaling involved in the metastatic progression.

  6. Expression of p13MTCP1 is restricted to mature T-cell proliferations with t(X;14) translocations.

    Science.gov (United States)

    Madani, A; Choukroun, V; Soulier, J; Cacheux, V; Claisse, J F; Valensi, F; Daliphard, S; Cazin, B; Levy, V; Leblond, V; Daniel, M T; Sigaux, F; Stern, M H

    1996-03-01

    T-cell prolymphocytic leukemia (T-PLL), a rare form of mature T-cell leukemias, and ataxia telangiectasia clonal proliferation, a related condition occurring in patients suffering from ataxia telangiectasia, have been associated to translocations involving the 14q32.1 or Xq28 regions, where are located the TCL1 and MTCP1 putative oncogenes, respectively. The MTCP1 gene is involved in the t(X;14)(q28;q11) translocation associated with these T-cell proliferations. Alternative splicing generates type A and B transcripts that potentially encode two entirely distinct proteins; type A transcripts code for a small mitochondrial protein, p8MTCP1, and type B transcripts, containing an additional open reading frame, may code for 107 amino-acid protein, p13MTCP1. The recently cloned TCL1 gene, also involved in translocations and inversions associated with T-cell proliferations, codes for a 14-kD protein that displays significant homology with p13MTCP1. We have generated rabbit antisera against this putative p13MTCP1 protein and screened for expression of p13MTCP1 normal lymphoid tissues and 33 cases of immature and mature lymphoid T-cell proliferations using a sensitive Western blot assay. We also investigated the MTCP1 locus configuration by Southern blot analysis. The p13MTCP1 protein was detected in the three T-cell proliferations with MTCP1 rearrangements because of t(X;14) translocations, but neither in normal resting and activated lymphocytes nor in the other T-cell leukemias. Our data support the hypothesis that p13MTCP1 and p14TCL1 form a new protein family that plays a key role in the pathogenesis of T-PLL and related conditions.

  7. The efficiency of photovoltaic cells exposed to pulsed laser light

    Science.gov (United States)

    Lowe, R. A.; Landis, G. A.; Jenkins, P.

    1993-01-01

    Future space missions may use laser power beaming systems with a free electron laser (FEL) to transmit light to a photovoltaic array receiver. To investigate the efficiency of solar cells with pulsed laser light, several types of GaAs, Si, CuInSe2, and GaSb cells were tested with the simulated pulse format of the induction and radio frequency (RF) FEL. The induction pulse format was simulated with an 800-watt average power copper vapor laser and the RF format with a frequency-doubled mode-locked Nd:YAG laser. Averaged current vs bias voltage measurements for each cell were taken at various optical power levels and the efficiency measured at the maximum power point. Experimental results show that the conversion efficiency for the cells tested is highly dependent on cell minority carrier lifetime, the width and frequency of the pulses, load impedance, and the average incident power. Three main effects were found to decrease the efficiency of solar cells exposed to simulated FEL illumination: cell series resistance, LC 'ringing', and output inductance. Improvements in efficiency were achieved by modifying the frequency response of the cell to match the spectral energy content of the laser pulse with external passive components.

  8. Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Sabanero, M.; Flores V, L. L. [Universidad de Guanajuato, Departamento de Biologia, DCNE, Noria Alta s/n, 36250 Guanajuato, Gto. (Mexico); Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, DCI, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Castruita D, J. P. [Universidad de Guadalajara, Departamento de Ecologia, CUCBA, Las Agujas, 45100 Zapopan, Jalisco (Mexico); Barbosa S, G., E-mail: myrna.sabanero@gmail.com [Universidad de Guanajuato, Departamento de Ciencias Medicas, DCS, 20 de Enero No. 929, Col. Obregon, 37000 Leon, Guanajuato (Mexico)

    2015-10-15

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H{sub 2}O{sub 2}/1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

  9. SHP-1 overexpression increases the radioresistance of NPC cells by enhancing DSB repair, increasing S phase arrest and decreasing cell apoptosis.

    Science.gov (United States)

    Pan, Xiaofen; Mou, Jingjing; Liu, Sha; Sun, Ziyi; Meng, Rui; Zhou, Zhenwei; Wu, Gang; Peng, Gang

    2015-06-01

    The present study aimed to investigate the influence of SHP-1 on the radioresistance of the nasopharyngeal carcinoma (NPC) cell line CNE-2 and the relevant underlying mechanisms. The human NPC cell line CNE-2 was transfected with a lentivirus that contained the SHP-1 gene or a nonsense sequence (referred to as LP-H1802Lv201 and LP-NegLv201 cells, respectively). Cells were irradiated with different ionizing radiation (IR) doses. Cell survival, DNA double-strand breaks (DSBs), apoptosis, cell cycle distribution, and the expression of related proteins were assessed using colony formation assay, immunofluorescent assays (IFAs), flow cytometry (FCM) and western blot analyses, respectively. Compared with the control (CNE-2 cells) and LP-NegLv201 cells, LP-H1802Lv201 cells were more resistant to IR. IFAs showed that IR caused less histone H2AX phosphorylation (γH2AX) and RAD51 foci in the LP-H1802Lv201 cells. Compared with the control and LP-NegLv201 cells, LP-H1802Lv201 cells showed increased S phase arrest. After IR, the apoptotic rate of the LP-H1802Lv201 cells was lower in contrast to the control and LP-NegLv201 cells. Western blot analyses showed that IR increased the phosphorylation of ataxia telangiectasia mutated (ATM) kinase, checkpoint kinase 2 (CHK2), ataxia telangiectasia and Rad3-related (ATR) protein, checkpoint kinase 1 (CHK1) and p53. In LP-H1802Lv201 cells, the phosphorylation levels of ATM and CHK2 were significantly increased while the p53 phosphorylation level was decreased compared to these levels in the control and LP-NegLv201 cells. Phosphorylation of ATR and CHK1 did not show significant differences in the three cell groups. Overexpression of SHP-1 in the CNE-2 cells led to radioresistance and the radioresistance was related to enhanced DNA DSB repair, increased S phase arrest and decreased cell apoptosis.

  10. Chronic Replication Problems Impact Cell Morphology and Adhesion of DNA Ligase I Defective Cells.

    Directory of Open Access Journals (Sweden)

    Paolo Cremaschi

    Full Text Available Moderate DNA damage resulting from metabolic activities or sub-lethal doses of exogenous insults may eventually lead to cancer onset. Human 46BR.1G1 cells bear a mutation in replicative DNA ligase I (LigI which results in low levels of replication-dependent DNA damage. This replication stress elicits a constitutive phosphorylation of the ataxia telangiectasia mutated (ATM checkpoint kinase that fails to arrest cell cycle progression or to activate apoptosis or cell senescence. Stable transfection of wild type LigI, as in 7A3 cells, prevents DNA damage and ATM activation. Here we show that parental 46BR.1G1 and 7A3 cells differ in important features such as cell morphology, adhesion and migration. Comparison of gene expression profiles in the two cell lines detects Bio-Functional categories consistent with the morphological and migration properties of LigI deficient cells. Interestingly, ATM inhibition makes 46BR.1G1 more similar to 7A3 cells for what concerns morphology, adhesion and expression of cell-cell adhesion receptors. These observations extend the influence of the DNA damage response checkpoint pathways and unveil a role for ATM kinase activity in modulating cell biology parameters relevant to cancer progression.

  11. Chronic Replication Problems Impact Cell Morphology and Adhesion of DNA Ligase I Defective Cells.

    Science.gov (United States)

    Cremaschi, Paolo; Oliverio, Matteo; Leva, Valentina; Bione, Silvia; Carriero, Roberta; Mazzucco, Giulia; Palamidessi, Andrea; Scita, Giorgio; Biamonti, Giuseppe; Montecucco, Alessandra

    2015-01-01

    Moderate DNA damage resulting from metabolic activities or sub-lethal doses of exogenous insults may eventually lead to cancer onset. Human 46BR.1G1 cells bear a mutation in replicative DNA ligase I (LigI) which results in low levels of replication-dependent DNA damage. This replication stress elicits a constitutive phosphorylation of the ataxia telangiectasia mutated (ATM) checkpoint kinase that fails to arrest cell cycle progression or to activate apoptosis or cell senescence. Stable transfection of wild type LigI, as in 7A3 cells, prevents DNA damage and ATM activation. Here we show that parental 46BR.1G1 and 7A3 cells differ in important features such as cell morphology, adhesion and migration. Comparison of gene expression profiles in the two cell lines detects Bio-Functional categories consistent with the morphological and migration properties of LigI deficient cells. Interestingly, ATM inhibition makes 46BR.1G1 more similar to 7A3 cells for what concerns morphology, adhesion and expression of cell-cell adhesion receptors. These observations extend the influence of the DNA damage response checkpoint pathways and unveil a role for ATM kinase activity in modulating cell biology parameters relevant to cancer progression.

  12. T-cell-specific deletion of Mof blocks their differentiation and results in genomic instability in mice.

    Science.gov (United States)

    Gupta, Arun; Hunt, Clayton R; Pandita, Raj K; Pae, Juhee; Komal, K; Singh, Mayank; Shay, Jerry W; Kumar, Rakesh; Ariizumi, Kiyoshi; Horikoshi, Nobuo; Hittelman, Walter N; Guha, Chandan; Ludwig, Thomas; Pandita, Tej K

    2013-05-01

    Ataxia telangiectasia patients develop lymphoid malignancies of both B- and T-cell origin. Similarly, ataxia telangiectasia mutated (Atm)-deficient mice exhibit severe defects in T-cell maturation and eventually develop thymomas. The function of ATM is known to be influenced by the mammalian orthologue of the Drosophila MOF (males absent on the first) gene. Here, we report the effect of T-cell-specific ablation of the mouse Mof (Mof) gene on leucocyte trafficking and survival. Conditional Mof(Flox/Flox) (Mof (F/F)) mice expressing Cre recombinase under control of the T-cell-specific Lck proximal promoter (Mof(F/F)/Lck-Cre(+)) display a marked reduction in thymus size compared with Mof(F/F)/Lck-Cre(-) mice. In contrast, the spleen size of Mof(F/F)/Lck-Cre(+) mice was increased compared with control Mof(F/F)/Lck-Cre(-) mice. The thymus of Mof(F/F)/Lck-Cre(+) mice contained significantly reduced T cells, whereas thymic B cells were elevated. Within the T-cell population, CD4(+)CD8(+) double-positive T-cell levels were reduced, whereas the immature CD4(-)CD8(-) double-negative (DN) population was elevated. Defective T-cell differentiation is also evident as an increased DN3 (CD44(-)CD25(+)) population, the cell stage during which T-cell receptor rearrangement takes place. The differentiation defect in T cells and reduced thymus size were not rescued in a p53-deficient background. Splenic B-cell distributions were similar between Mof(F/F)/Lck-Cre(+) and Mof(F/F)/Lck-Cre(-) mice except for an elevation of the κ light-chain population, suggestive of an abnormal clonal expansion. T cells from Mof(F/F)/Lck-Cre(+) mice did not respond to phytohaemagglutinin (PHA) stimulation, whereas LPS-stimulated B cells from Mof(F/F)/Lck-Cre(+) mice demonstrated spontaneous genomic instability. Mice with T-cell-specific loss of MOF had shorter lifespans and decreased survival following irradiation than did Mof(F/F)/Lck-Cre(-) mice. These observations suggest that Mof plays a critical

  13. Impaired NK Cell Activation and Chemotaxis toward Dendritic Cells Exposed to Complement-Opsonized HIV-1

    Science.gov (United States)

    Ellegård, Rada; Crisci, Elisa; Andersson, Jonas; Shankar, Esaki M.; Nyström, Sofia; Hinkula, Jorma

    2015-01-01

    Mucosa resident dendritic cells (DCs) may represent one of the first immune cells that HIV-1 encounters during sexual transmission. The virions in body fluids can be opsonized with complement factors because of HIV-mediated triggering of the complement cascade, and this appears to influence numerous aspects of the immune defense targeting the virus. One key attribute of host defense is the ability to attract immune cells to the site of infection. In this study, we investigated whether the opsonization of HIV with complement (C-HIV) or a mixture of complement and Abs (CI-HIV) affected the cytokine and chemokine responses generated by DCs, as well as their ability to attract other immune cells. We found that the expression levels of CXCL8, CXCL10, CCL3, and CCL17 were lowered after exposure to either C-HIV or CI-HIV relative to free HIV (F-HIV). DCs exposed to F-HIV induced higher cell migration, consisting mainly of NK cells, compared with opsonized virus, and the chemotaxis of NK cells was dependent on CCL3 and CXCL10. NK cell exposure to supernatants derived from HIV-exposed DCs showed that F-HIV induced phenotypic activation (e.g., increased levels of TIM3, CD69, and CD25) and effector function (e.g., production of IFNγ and killing of target cells) in NK cells, whereas C-HIV and CI-HIV did not. The impairment of NK cell recruitment by DCs exposed to complement-opsonized HIV and the lack of NK activation may contribute to the failure of innate immune responses to control HIV at the site of initial mucosa infection. PMID:26157174

  14. Proteome analysis of proliferative response of bystander cells adjacent to cells exposed to ionizing radiation.

    Science.gov (United States)

    Gerashchenko, Bogdan I; Yamagata, Akira; Oofusa, Ken; Yoshizato, Katsutoshi; de Toledo, Sonia M; Howell, Roger W

    2007-06-01

    Recently (Cytometry 2003, 56A, 71-80), we reported that direct cell-to-cell contact is required for stimulating proliferation of bystander rat liver cells (WB-F344) cocultured with irradiated cells, and neither functional gap junction intercellular communication nor long-range extracellular factors appear to be involved in this proliferative bystander response (PBR). The molecular basis for this response is unknown. Confluent monolayers of WB-F344 cells were exposed to 5-Gray (Gy) of gamma-rays. Irradiated cells were mixed with unirradiated cells and co-cultured for 24 h. Cells were harvested and protein expression was examined using 2-DE. Protein expression was also determined in cultures of unirradiated and 5-Gy irradiated cells. Proteins were identified by MS. Nucleophosmin (NPM)-1, a multifunctional nucleolar protein, was more highly expressed in bystander cells than in either unirradiated or 5-Gy irradiated cells. Enolase-alpha, a glycolytic enzyme, was present in acidic and basic variants in unirradiated cells. In bystander and 5-Gy irradiated cells, the basic variant was weakly expressed, whereas the acidic variant was overwhelmingly present. These data indicate that the presence of irradiated cells can affect NPM-1 and enolase-alpha in adjacent bystander cells. These proteins appear to participate in molecular events related to the PBR and suggest that this response may involve cellular defense, proliferation, and metabolism.

  15. B cells exposed to enterobacterial components suppress development of experimental colitis

    DEFF Research Database (Denmark)

    Schmidt, Esben Gjerløff Wedebye; Larsen, Hjalte List; Kristensen, Nanna Ny

    2012-01-01

    BACKGROUND: B cells positively contribute to immunity by antigen presentation to CD4(+) T cells, cytokine production, and differentiation into antibody secreting plasma cells. Accumulating evidence implies that B cells also possess immunoregulatory functions closely linked to their capability of IL......-10 secretion. METHODS: Colitis development was followed in CD4(+) CD25(-) T cell transplanted SCID mice co-transferred with B cells exposed to an enterobacterial extract (ebx-B cells). B and T cell cytokine expression was measured by flow cytometry and enzyme-linked immunosorbent assay (ELISA......). RESULTS: We demonstrate that splenic B cells exposed to ebx produce large amounts of IL-10 in vitro and express CD1d and CD5 previously known to be associated with regulatory B cells. In SCID mice transplanted with colitogenic CD4(+) CD25(-) T cells, co-transfer of ebx-B cells significantly suppressed...

  16. Early B-cell Specific Inactivation of ATM Synergizes with Ectopic CyclinD1 Expression to Promote Pre-germinal center B-cell Lymphomas in Mice

    Science.gov (United States)

    Yamamoto, Kenta; Lee, Brian J.; Li, Chen; Dubois, Richard L.; Hobeika, Elias; Bhagat, Govind; Zha, Shan

    2017-01-01

    Ataxia Telangiectasia Mutated (ATM) kinase is a master regulator of the DNA damage response. ATM is frequently inactivated in human B-cell non-Hodgkin Lymphomas (B-NHL), including ~50% of mantle cell lymphomas (MCLs) characterized by ectopic expression of CyclinD1. Here we report that early and robust deletion of ATM in precursor/progenitor B-cells causes cell-autonomous, clonal mature B cell lymphomas of both pre- and post-germinal center (GC) origins. Unexpectedly naïve B cell specific deletion of ATM is not sufficient to induce lymphomas in mice, highlighting the important tumor suppressor function of ATM in immature B cells. While EμCyclinD1 is not sufficient to induce lymphomas, EμCyclinD1 accelerates the kinetics and increased the incidence of clonal lymphomas in ATM-deficient B-cells and skews the lymphomas towards pre-GC derived small lymphocytic neoplasms sharing morphological features of human MCL. This is in part due to CyclinD1-driven expansion of ATM-deficient naïve B cells with genomic instability, which promotes the deletions of additional tumor suppressor genes (i.g. Trp53, Mll2, Rb1 and Cdkn2a). Together these findings define a synergistic function of ATM and CyclinD1 in pre-germinal center B-cell proliferation and lymphomagenesis and provide a prototypic animal model to study the pathogenesis of human MCL. PMID:25676421

  17. Early B-cell-specific inactivation of ATM synergizes with ectopic CyclinD1 expression to promote pre-germinal center B-cell lymphomas in mice.

    Science.gov (United States)

    Yamamoto, K; Lee, B J; Li, C; Dubois, R L; Hobeika, E; Bhagat, G; Zha, S

    2015-06-01

    Ataxia telangiectasia-mutated (ATM) kinase is a master regulator of the DNA damage response. ATM is frequently inactivated in human B-cell non-Hodgkin lymphomas, including ~50% of mantle cell lymphomas (MCLs) characterized by ectopic expression of CyclinD1. Here we report that early and robust deletion of ATM in precursor/progenitor B cells causes cell autonomous, clonal mature B-cell lymphomas of both pre- and post-germinal center (GC) origins. Unexpectedly, naive B-cell-specific deletion of ATM is not sufficient to induce lymphomas in mice, highlighting the important tumor suppressor function of ATM in immature B cells. Although EμCyclinD1 is not sufficient to induce lymphomas, EμCyclinD1 accelerates the kinetics and increases the incidence of clonal lymphomas in ATM-deficient B-cells and skews the lymphomas toward pre-GC-derived small lymphocytic neoplasms, sharing morphological features of human MCL. This is in part due to CyclinD1-driven expansion of ATM-deficient naive B cells with genomic instability, which promotes the deletions of additional tumor suppressor genes (i.e. Trp53, Mll2, Rb1 and Cdkn2a). Together these findings define a synergistic function of ATM and CyclinD1 in pre-GC B-cell proliferation and lymphomagenesis and provide a prototypic animal model to study the pathogenesis of human MCL.

  18. Transcriptional Profiling of Human Peripheral Blood Mononuclear Cells Exposed to Bacillus anthracis in vitro

    Science.gov (United States)

    2013-03-11

    Bacillus cereus group of bacteria, are attributed to poly- γ-D-glutamate acid (PGA) capsule, lethal toxin (LT) and edema toxin (ET) [10-12]. These toxins...M, Hellman M, Muhie S, et al. (2013) Transcriptional Profiling of Human Peripheral Blood Mononuclear Cells Exposed to Bacillus anthracis in vitro...author and source are credited. Transcriptional Profiling of Human Peripheral Blood Mononuclear Cells Exposed to Bacillus anthracis in vitro Rasha

  19. Viscoelastic properties of vascular endothelial cells exposed to uniaxial stretch

    Science.gov (United States)

    Osterday, Kathryn; Chew, Thomas; Loury, Phillip; Haga, Jason; Del Alamo, Juan C.; Chien, Shu

    2011-11-01

    Vascular endothelial cells (VECs) line the interior of blood vessels and regulate a variety of functions in the cardiovascular system. It is widely accepted that VECs will remodel themselves in response to mechanical stimuli, but few studies have analyzed the mechanical properties of these cells under stretch. We hypothesize that uniaxial stretch will cause an anisotropic realignment of actin filaments, and a change in the viscoelastic properties of the cell. To test this hypothesis, VECs were grown on a thin, transparent membrane mounted on a microscope. The membrane was stretched, consequently stretching the cells. Time-lapse sequences of the cells were taken every hour with a time resolution of 10 Hz. The random trajectories of intracellular endogenous particles were tracked using in-house algorithms. These trajectories were analyzed using a novel particle tracking microrheology formulation that takes into account the anisotropy of the cytoplasm of VECs. Supported by NSF CBET-1055697 CAREER Award (JCA) and NIH grants BRP HL064382 (SC), 1R01 HL080518 (SC).

  20. Correlation between dielectric property by dielectrophoretic levitation and growth activity of cells exposed to electric field.

    Science.gov (United States)

    Hakoda, Masaru; Hirota, Yusuke

    2013-09-01

    The purpose of this study is to develop a system analyzing cell activity by the dielectrophoresis method. Our previous studies revealed a correlation between the growth activity and dielectric property (Re[K(ω)]) of mouse hybridoma 3-2H3 cells using dielectrophoretic levitation. Furthermore, it was clarified that the differentiation activity of many stem cells could be evaluated by the Re[K(ω)] without differentiation induction. In this paper, 3-2H3 cells exposed to an alternating current (AC) electric field or a direct current (DC) electric field were cultivated, and the influence of damage by the electric field on the growth activity of the cells was examined. To evaluate the activity of the cells by measuring the Re[K(ω)], the correlation between the growth activity and the Re[K(ω)] of the cells exposed to the electric field was examined. The relations between the cell viability, growth activity, and Re[K(ω)] in the cells exposed to the AC electric field were obtained. The growth activity of the cells exposed to the AC electric field could be evaluated by the Re[K(ω)]. Furthermore, it was found that the adverse effects of the electric field on the cell viability and the growth activity were smaller in the AC electric field than the DC electric field.

  1. Kaempferol induces DNA damage and inhibits DNA repair associated protein expressions in human promyelocytic leukemia HL-60 cells.

    Science.gov (United States)

    Wu, Lung-Yuan; Lu, Hsu-Feng; Chou, Yu-Cheng; Shih, Yung-Luen; Bau, Da-Tian; Chen, Jaw-Chyun; Hsu, Shu-Chun; Chung, Jing-Gung

    2015-01-01

    Numerous evidences have shown that plant flavonoids (naturally occurring substances) have been reported to have chemopreventive activities and protect against experimental carcinogenesis. Kaempferol, one of the flavonoids, is widely distributed in fruits and vegetables, and may have cancer chemopreventive properties. However, the precise underlying mechanism regarding induced DNA damage and suppressed DNA repair system are poorly understood. In this study, we investigated whether kaempferol induced DNA damage and affected DNA repair associated protein expression in human leukemia HL-60 cells in vitro. Percentages of viable cells were measured via a flow cytometry assay. DNA damage was examined by Comet assay and DAPI staining. DNA fragmentation (ladder) was examined by DNA gel electrophoresis. The changes of protein levels associated with DNA repair were examined by Western blotting. Results showed that kaempferol dose-dependently decreased the viable cells. Comet assay indicated that kaempferol induced DNA damage (Comet tail) in a dose-dependent manner and DAPI staining also showed increased doses of kaempferol which led to increased DNA condensation, these effects are all of dose-dependent manners. Western blotting indicated that kaempferol-decreased protein expression associated with DNA repair system, such as phosphate-ataxia-telangiectasia mutated (p-ATM), phosphate-ataxia-telangiectasia and Rad3-related (p-ATR), 14-3-3 proteins sigma (14-3-3σ), DNA-dependent serine/threonine protein kinase (DNA-PK), O(6)-methylguanine-DNA methyltransferase (MGMT), p53 and MDC1 protein expressions, but increased the protein expression of p-p53 and p-H2AX. Protein translocation was examined by confocal laser microscopy, and we found that kaempferol increased the levels of p-H2AX and p-p53 in HL-60 cells. Taken together, in the present study, we found that kaempferol induced DNA damage and suppressed DNA repair and inhibited DNA repair associated protein expression in HL-60

  2. Subamolide a induces mitotic catastrophe accompanied by apoptosis in human lung cancer cells.

    Science.gov (United States)

    Hung, Jen-Yu; Wen, Ching-Wen; Hsu, Ya-Ling; Lin, En-Shyh; Huang, Ming-Shyan; Chen, Chung-Yi; Kuo, Po-Lin

    2013-01-01

    This study investigated the anticancer effects of subamolide A (Sub-A), isolated from Cinnamomum subavenium, on human nonsmall cell lung cancer cell lines A549 and NCI-H460. Treatment of cancer cells with Sub-A resulted in decreased cell viability of both lung cancer cell lines. Sub-A induced lung cancer cell death by triggering mitotic catastrophe with apoptosis. It triggered oxidant stress, indicated by increased cellular reactive oxygen species (ROS) production and decreased glutathione level. The elevated ROS triggered the activation of ataxia-telangiectasia mutation (ATM), which further enhanced the ATF3 upregulation and subsequently enhanced p53 function by phosphorylation at Serine 15 and Serine 392. The antioxidant, EUK8, significantly decreased mitotic catastrophe by inhibiting ATM activation, ATF3 expression, and p53 phosphorylation. The reduction of ATM and ATF3 expression by shRNA decreased Sub-A-mediated p53 phosphorylation and mitotic catastrophe. Sub-A also caused a dramatic 70% reduction in tumor size in an animal model. Taken together, cell death of lung cancer cells in response to Sub-A is dependent on ROS generation, which triggers mitotic catastrophe followed by apoptosis. Therefore, Sub-A may be a novel anticancer agent for the treatment of nonsmall cell lung cancer.

  3. Subamolide A Induces Mitotic Catastrophe Accompanied by Apoptosis in Human Lung Cancer Cells

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    Jen-Yu Hung

    2013-01-01

    Full Text Available This study investigated the anticancer effects of subamolide A (Sub-A, isolated from Cinnamomum subavenium, on human nonsmall cell lung cancer cell lines A549 and NCI-H460. Treatment of cancer cells with Sub-A resulted in decreased cell viability of both lung cancer cell lines. Sub-A induced lung cancer cell death by triggering mitotic catastrophe with apoptosis. It triggered oxidant stress, indicated by increased cellular reactive oxygen species (ROS production and decreased glutathione level. The elevated ROS triggered the activation of ataxia-telangiectasia mutation (ATM, which further enhanced the ATF3 upregulation and subsequently enhanced p53 function by phosphorylation at Serine 15 and Serine 392. The antioxidant, EUK8, significantly decreased mitotic catastrophe by inhibiting ATM activation, ATF3 expression, and p53 phosphorylation. The reduction of ATM and ATF3 expression by shRNA decreased Sub-A-mediated p53 phosphorylation and mitotic catastrophe. Sub-A also caused a dramatic 70% reduction in tumor size in an animal model. Taken together, cell death of lung cancer cells in response to Sub-A is dependent on ROS generation, which triggers mitotic catastrophe followed by apoptosis. Therefore, Sub-A may be a novel anticancer agent for the treatment of nonsmall cell lung cancer.

  4. Autosomal mutants of proton-exposed kidney cells display frequent loss of heterozygosity on nonselected chromosomes.

    Science.gov (United States)

    Grygoryev, Dmytro; Dan, Cristian; Gauny, Stacey; Eckelmann, Bradley; Ohlrich, Anna P; Connolly, Marissa; Lasarev, Michael; Grossi, Gianfranco; Kronenberg, Amy; Turker, Mitchell S

    2014-05-01

    High-energy protons found in the space environment can induce mutations and cancer, which are inextricably linked. We hypothesized that some mutants isolated from proton-exposed kidneys arose through a genome-wide incident that causes loss of heterozygosity (LOH)-generating mutations on multiple chromosomes (termed here genomic LOH). To test this hypothesis, we examined 11 pairs of nonselected chromosomes for LOH events in mutant cells isolated from the kidneys of mice exposed to 4 or 5 Gy of 1 GeV protons. The mutant kidney cells were selected for loss of expression of the chromosome 8-encoded Aprt gene. Genomic LOH events were also assessed in Aprt mutants isolated from isogenic cultured kidney epithelial cells exposed to 5 Gy of protons in vitro. Control groups were spontaneous Aprt mutants and clones isolated without selection from the proton-exposed kidneys or cultures. The in vivo results showed significant increases in genomic LOH events in the Aprt mutants from proton-exposed kidneys when compared with spontaneous Aprt mutants and when compared with nonmutant (i.e., nonselected) clones from the proton-exposed kidneys. A bias for LOH events affecting chromosome 14 was observed in the proton-induced Aprt mutants, though LOH for this chromosome did not confer increased radiation resistance. Genomic LOH events were observed in Aprt mutants isolated from proton-exposed cultured kidney cells; however the incidence was fivefold lower than in Aprt mutants isolated from exposed intact kidneys, suggesting a more permissive environment in the intact organ and/or the evolution of kidney clones prior to their isolation from the tissue. We conclude that proton exposure creates a subset of viable cells with LOH events on multiple chromosomes, that these cells form and persist in vivo, and that they can be isolated from an intact tissue by selection for a mutation on a single chromosome.

  5. Signalling pathways induced in cells exposed to medium from irradiated cells

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    Lyng, F.M.; Maguire, P. (Radiation and Environmental Science Centre, Focas Institute, Dublin Institute of Technology, Dublin (Ireland)); McClean, B.; Seymour, C.; Mothersill, C. (St Luke' s Hospital, Dublin (Ireland))

    2008-12-15

    In recent years, radiation induced bystander effects have been reported in cells which were not themselves irradiated but were either in the vicinity of irradiated cells or exposed to medium from irradiated cells. The effects have been clearly shown to occur both in vivo and in vitro. This work has led to a paradigm shift in radiobiology over the last 5 - 10 years. The target theory of radiation induced effects is now being challenged because of an increasing number of studies which demonstrate non(DNA)-targeted effects. These effects appear to be particularly important at low doses. Considerable evidence now exists relating to radiation-induced bystander effects but the mechanisms involved in the transduction of the signal are still unclear. Cell - cell communication through gap junctions and / or secretion of a cytotoxic factor into the medium are thought to be involved in the transduction of the bystander signal. Oxidative metabolism has been shown to be important in both mechanisms. Signalling pathways leading to apoptosis, such as calcium, MAP kinase, mitochondrial and reactive oxygen species (ROS) signalling are discussed. The importance of oxidative metabolism and calcium signalling in bystander responses are demonstrated. Further investigations of these signalling pathways may aid in the identification of novel therapeutic targets. (orig.)

  6. ATM Inhibition Potentiates Death of Androgen Receptor-inactivated Prostate Cancer Cells with Telomere Dysfunction.

    Science.gov (United States)

    Reddy, Vidyavathi; Wu, Min; Ciavattone, Nicholas; McKenty, Nathan; Menon, Mani; Barrack, Evelyn R; Reddy, G Prem-Veer; Kim, Sahn-Ho

    2015-10-16

    Androgen receptor (AR) plays a role in maintaining telomere stability in prostate cancer cells, as AR inactivation induces telomere dysfunction within 3 h. Since telomere dysfunction in other systems is known to activate ATM (ataxia telangiectasia mutated)-mediated DNA damage response (DDR) signaling pathways, we investigated the role of ATM-mediated DDR signaling in AR-inactivated prostate cancer cells. Indeed, the induction of telomere dysfunction in cells treated with AR-antagonists (Casodex or MDV3100) or AR-siRNA was associated with a dramatic increase in phosphorylation (activation) of ATM and its downstream effector Chk2 and the presenceof phosphorylated ATM at telomeres, indicating activation of DDR signaling at telomeres. Moreover, Casodex washout led to the reversal of telomere dysfunction, indicating repair of damaged telomeres. ATM inhibitor blocked ATM phosphorylation, induced PARP cleavage, abrogated cell cycle checkpoint activation and attenuated the formation of γH2AX foci at telomeres in AR-inactivated cells, suggesting that ATM inhibitor induces apoptosis in AR-inactivated cells by blocking the repair of damaged DNA at telomeres. Finally, colony formation assay revealed a dramatic decrease in the survival of cells co-treated with Casodex and ATM inhibitor as compared with those treated with either Casodex or ATM inhibitor alone. These observations indicate that inhibitors of DDR signaling pathways may offer a unique opportunity to enhance the potency of AR-targeted therapies for the treatment of androgen-sensitive as well as castration-resistant prostate cancer.

  7. Methylseleninic acid sensitizes Notch3-activated OVCA429 ovarian cancer cells to carboplatin.

    Directory of Open Access Journals (Sweden)

    Tiffany J Tzeng

    Full Text Available Ovarian cancer, the deadliest of gynecologic cancers, is usually not diagnosed until advanced stages. Although carboplatin has been popular for treating ovarian cancer for decades, patients eventually develop resistance to this platinum-containing drug. Expression of neurogenic locus notch homolog 3 (Notch3 is associated with chemoresistance and poor overall survival in ovarian cancer patients. Overexpression of NICD3 (the constitutively active form of Notch3 in OVCA429 ovarian cancer cells (OVCA429/NICD3 renders them resistance to carboplatin treatment compared to OVCA429/pCEG cells expressing an empty vector. We have previously shown that methylseleninic acid (MSeA induces oxidative stress and activates ataxia-telangiectasia mutated and DNA-dependent protein kinase in cancer cells. Here we tested the hypothesis that MSeA and carboplatin exerted a synthetic lethal effect on OVCA429/NICD3 cells. Co-treatment with MSeA synergistically sensitized OVCA429/NICD3 but not OVCA429/pCEG cells to the killing by carboplatin. This synergism was associated with a cell cycle exit at the G2/M phase and the induction of NICD3 target gene HES1. Treatment of N-acetyl cysteine or inhibitors of the above two kinases did not directly impact on the synergism in OVCA429/NICD3 cells. Taken together, these results suggest that the efficacy of carboplatin in the treatment of high grade ovarian carcinoma can be enhanced by a combinational therapy with MSeA.

  8. Dengue-induced autophagy, virus replication and protection from cell death require ER stress (PERK) pathway activation.

    Science.gov (United States)

    Datan, E; Roy, S G; Germain, G; Zali, N; McLean, J E; Golshan, G; Harbajan, S; Lockshin, R A; Zakeri, Z

    2016-03-03

    A virus that reproduces in a host without killing cells can easily establish a successful infection. Previously, we showed that dengue-2, a virus that threatens 40% of the world, induces autophagy, enabling dengue to reproduce in cells without triggering cell death. Autophagy further protects the virus-laden cells from further insults. In this study, we evaluate how it does so; we show that dengue upregulates host pathways that increase autophagy, namely endoplasmic reticulum (ER) stress and ataxia telangiectasia mutated (ATM) signaling followed by production of reactive oxygen species (ROS). Inhibition of ER stress or ATM signaling abrogates the dengue-conferred protection against other cell stressors. Direct inhibition of ER stress response in infected cells decreases autophagosome turnover, reduces ROS production and limits reproduction of dengue virus. Blocking ATM activation, which is an early response to infection, decreases transcription of ER stress response proteins, but ATM has limited impact on production of ROS and virus titers. Production of ROS determines only late-onset autophagy in infected cells and is not necessary for dengue-induced protection from stressors. Collectively, these results demonstrate that among the multiple autophagy-inducing pathways during infection, ER stress signaling is more important to viral replication and protection of cells than either ATM or ROS-mediated signaling. To limit virus production and survival of dengue-infected cells, one must address the earliest phase of autophagy, induced by ER stress.

  9. Modeling the role of p53 pulses in DNA damage- induced cell death decision

    Directory of Open Access Journals (Sweden)

    Cui Jun

    2009-06-01

    Full Text Available Abstract Background The tumor suppressor p53 plays pivotal roles in tumorigenesis suppression. Although oscillations of p53 have been extensively studied, the mechanism of p53 pulses and their physiological roles in DNA damage response remain unclear. Results To address these questions we presented an integrated model in which Ataxia-Telangiectasia Mutated (ATM activation and p53 oscillation were incorporated with downstream apoptotic events, particularly the interplays between Bcl-2 family proteins. We first reproduced digital oscillation of p53 as the response of normal cells to DNA damage. Subsequent modeling in mutant cells showed that high basal DNA damage is a plausible cause for sustained p53 pulses observed in tumor cells. Further computational analyses indicated that p53-dependent PUMA accumulation and the PUMA-controlled Bax activation switch might play pivotal roles to count p53 pulses and thus decide the cell fate. Conclusion The high levels of basal DNA damage are responsible for generating sustained pulses of p53 in the tumor cells. Meanwhile, the Bax activation switch can count p53 pulses through PUMA accumulation and transfer it into death signal. Our modeling provides a plausible mechanism about how cells generate and orchestrate p53 pulses to tip the balance between survival and death.

  10. Mechanistic Rationale to Target PTEN-Deficient Tumor Cells with Inhibitors of the DNA Damage Response Kinase ATM.

    Science.gov (United States)

    McCabe, Nuala; Hanna, Conor; Walker, Steven M; Gonda, David; Li, Jie; Wikstrom, Katarina; Savage, Kienan I; Butterworth, Karl T; Chen, Clark; Harkin, D Paul; Prise, Kevin M; Kennedy, Richard D

    2015-06-01

    Ataxia telangiectasia mutated (ATM) is an important signaling molecule in the DNA damage response (DDR). ATM loss of function can produce a synthetic lethal phenotype in combination with tumor-associated mutations in FA/BRCA pathway components. In this study, we took an siRNA screening strategy to identify other tumor suppressors that, when inhibited, similarly sensitized cells to ATM inhibition. In this manner, we determined that PTEN and ATM were synthetically lethal when jointly inhibited. PTEN-deficient cells exhibited elevated levels of reactive oxygen species, increased endogenous DNA damage, and constitutive ATM activation. ATM inhibition caused catastrophic DNA damage, mitotic cell cycle arrest, and apoptosis specifically in PTEN-deficient cells in comparison with wild-type cells. Antioxidants abrogated the increase in DNA damage and ATM activation in PTEN-deficient cells, suggesting a requirement for oxidative DNA damage in the mechanism of cell death. Lastly, the ATM inhibitor KU-60019 was specifically toxic to PTEN mutant cancer cells in tumor xenografts and reversible by reintroduction of wild-type PTEN. Together, our results offer a mechanistic rationale for clinical evaluation of ATM inhibitors in PTEN-deficient tumors.

  11. Correlativity study between expression of DNA double-strand break repair protein and radiosensitivity of tumor cells

    Institute of Scientific and Technical Information of China (English)

    Liang ZHUANG; Shiying YU; Xiaoyuan HUANG; Yang CAO; Huihua XIONG

    2009-01-01

    DNA double-strand break (DSB) is generally regarded as the most lethal of all DNA lesions after radiation. KuS0, DNA-PK catalytic subunit (DNA-PKcs) and ataxia telangiectasia mutated (ATM) proteins are major DSB repair proteins. In this study, survival fraction at 2Gy (SF2) values of eight human tumor cell lines (including four human cervical carcinoma cell lines HeLa, SiHa, C33A, Caski, three human breast carcinoma cell lines MCF-7, MDA-MB-231, MDA-MB-453, and one human lung carcinoma cell line A549) were acquired by clone formation assay, and western blot was applied to detect the expressions of Ku80, DNA-PKcs and ATM protein. The correlativity of protein expression with SF2 value was analyzed by Pearson linear correlation analysis. We found that the expression of the same protein in different cell lines and the expression of three proteins in the same cell line had a significant difference. The SF2 values were also different in eight tumor cell lines and there was a positive correlativity between the expression of DNA-PKcs and SF2 (r=0.723, P =0.043), but Ku80 and ATM expression had no correlation with SF2 (P>0.05). These findings suggest that the expression level of DNA-PKcs protein can be an indicator for predicting the radiosensitivity of tumor cells.

  12. Mannose-exposing myeloid leukemia cells detected by the sCAR-PPA fusion protein.

    Science.gov (United States)

    Li, Gong Chu; Li, Na; Zhang, Yan Hong; Li, Xin; Wang, Yi Gang; Liu, Xin Yuan; Qian, Wen Bin; Liu, Xiao Chuan

    2009-06-01

    Altered glycosylation may be a hallmark of malignant transformation and cancer progression. In the work described, a specific mannose-binding lectin, Pinellia pedatisecta agglutinin (PPA), was genetically fused with the extracellular domain of coxsackie-adenovirus receptor (CAR) to generate the soluble CAR (sCAR)-PPA fusion protein. The adenoviral transduction of acute myeloid leukemia (AML) cell lines Kasumi-1 and HL-60 was increased by sCAR-PPA, indicating that a fraction of AML cells exposing mannose residues was detected by PPA. However, sCAR-PPA did not increase the adenoviral infection of KG-1 cells, suggesting the mannose exposure of AML cells may be cell type specific. Furthermore, the infectious efficiency of Ad-EGFP in chronic myeloid leukemia cell line K562 was significantly increased by sCAR-PPA as well. We, herein, report that PPA recognized a fraction of myeloid leukemia cells showing mannose-exposing phenotype. The sCAR-PPA fusion protein combined with the adenoviral vector system may provide a useful tool for investigating myeloid leukemia cells exposing mannose residues and further elucidating the role of these cells in the leukemia development.

  13. AZD6738, a novel oral inhibitor of ATR, induces synthetic lethality with ATM-deficiency in gastric cancer cells.

    Science.gov (United States)

    Min, Ahrum; Im, Seock-Ah; Jang, Hyemin; Kim, Seongyeong; Lee, Miso; Kim, Debora Keunyoung; Yang, Yaewon; Kim, Hee-Jun; Lee, Kyung-Hun; Kim, Jin Won; Kim, Tae-Yong; Oh, Do-Youn; Brown, Jeff; Lau, Alan; O Connor, Mark J; Bang, Yung-Jue

    2017-01-30

    Ataxia telangiectasia and Rad3-related (ATR) can be considered an attractive target for cancer treatment due to its deleterious effect on cancer cells harboring a homologous recombination defect (HRD). The aim of this study was to investigate the potential use of the ATR inhibitor, AZD6738, to treat gastric cancer. In SNU-601 cells with dysfunctional ATM, AZD6738 treatment led to an accumulation of DNA damage due to dysfunctional RAD51 foci formation, S phase arrest, and caspase 3-dependent apoptosis. In contrast, SNU-484 cells with functional ATM were not sensitive to AZD6738. Inhibition of ATM in SNU-484 cells enhanced AZD6738 sensitivity to a level comparable with that observed in SNU-601 cells, showing that activation of the ATM-Chk2 signaling pathway attenuates AZD6738 sensitivity. In addition, decreased HDAC1 expression was found to be associated with ATM inactivation in SNU-601 cells, demonstrating the interaction between HDAC1 and ATM can affect sensitivity to AZD6738. Furthermore, in an in vivo tumor xenograft mouse model, AZD6738 significantly suppressed tumor growth and increased apoptosis. These findings suggest synthetic lethality between ATR inhibition and ATM-deficiency in gastric cancer cells. Further clinical studies on the interaction between AZD 6738 and ATM-deficiency are warranted to develop novel treatment strategies for gastric cancer.

  14. Activation of p53 in Human and Murine Cells by DNA-Damaging Agents Differentially Regulates Aryl Hydrocarbon Receptor Levels.

    Science.gov (United States)

    Panchanathan, Ravichandran; Liu, Hongzhu; Choubey, Divaker

    2015-01-01

    Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that regulates multiple cellular processes. The anticancer drug doxorubicin (DOX) can activate AhR-mediated transcription of target genes. Because DOX in cells activates a DNA damage response involving ataxia telangiectasia-mutated (ATM)-mediated activation of p53, we investigated whether the activation of the p53 in cells by DNA-damaging agents such as DOX or bleomycin could regulate the AhR levels. Here we report that activation of p53 by DNA-damaging agents in human cells increased levels of AhR through a posttranscriptional mechanism. Accordingly, fibroblasts from ATM patients, which are defective in p53 activation, expressed reduced constitutive levels of AhR and treatment of cells with bleomycin did not appreciably increase the AhR levels. Further, activation of p53 in cells stimulated the expression of AhR target genes. In murine cells, activation of p53 reduced the levels of AhR messenger RNA and protein and reduced the expression of AhR target genes. Our observations revealed that activation of p53 in human and murine cells differentially regulates AhR levels.

  15. Increased frequency of micronucleated exfoliated cells among humans exposed in vivo to mobile telephone radiations.

    Science.gov (United States)

    Yadav, Abhay Singh; Sharma, Manoj Kumar

    2008-02-29

    The health concerns have been raised following the enormous increase in the use of wireless mobile telephones throughout the world. This investigation had been taken, with the motive to find out whether mobile phone radiations cause any in vivo effects on the frequency of micronucleated exfoliated cells in the exposed subjects. A total of 109 subjects including 85 regular mobile phone users (exposed) and 24 non-users (controls) had participated in this study. Exfoliated cells were obtained by swabbing the buccal-mucosa from exposed as well as sex-age-matched controls. One thousand exfoliated cells were screened from each individual for nuclear anomalies including micronuclei (MN), karyolysis (KL), karyorrhexis (KH), broken egg (BE) and binucleated (BN) cells. The average daily duration of exposure to mobile phone radiations is 61.26 min with an overall average duration of exposure in term of years is 2.35 years in exposed subjects along with the 9.84+/-0.745 micronucleated cells (MNCs) and 10.72+/-0.889 total micronuclei (TMN) as compared to zero duration of exposure along with average 3.75+/-0.774 MNC and 4.00+/-0.808 TMN in controls. The means are significantly different in case of MNC and TMN at 0.01% level of significance. The mean of KL in controls is 13.17+/-2.750 and in exposed subjects is 13.06+/-1.793. The value of means of KH in exposed subjects (1.84+/-0.432) is slightly higher than in controls (1.42+/-0.737). Mean frequency of broken egg is found to be more in exposed subjects (0.65+/-0.276) as compared to controls (0.50+/-0.217). Frequency of presence of more than one nucleus in a cell (binucleated) is also higher in exposed (2.72+/-0.374) in comparison to controls (0.67+/-0.231). Although there is a slight increase in mean frequency of KH, BE and BN in exposed subjects but the difference is not found statistically significant. Correlation between 0-1, 1-2, 2-3 and 3-4 years of exposure and the frequency of MNC and TMN has been calculated and found to

  16. Cell cycle synchronization reveals greater G2/M-phase accumulation of lung epithelial cells exposed to titanium dioxide nanoparticles.

    Science.gov (United States)

    Medina-Reyes, Estefany I; Bucio-López, Laura; Freyre-Fonseca, Verónica; Sánchez-Pérez, Yesennia; García-Cuéllar, Claudia M; Morales-Bárcenas, Rocío; Pedraza-Chaverri, José; Chirino, Yolanda I

    2015-03-01

    Titanium dioxide has been classified in the 2B group as a possible human carcinogen by the International Agency for Research on Cancer, and amid concerns of its exposure, cell cycle alterations are an important one. However, several studies show inconclusive effects, mainly because it is difficult to compare cell cycle effects caused by TiO2 nanoparticle (NP) exposure between different shapes and sizes of NP, cell culture types, and time of exposure. In addition, cell cycle is frequently analyzed without cell cycle synchronization, which may also mask some effects. We hypothesized that synchronization after TiO2 NP exposure could reveal dissimilar cell cycle progression when compared with unsynchronized cell population. To test our hypothesis, we exposed lung epithelial cells to 1 and 10 μg/cm(2) TiO2 NPs for 7 days and one population was synchronized by serum starvation and inhibition of ribonucleotide reductase using hydroxyurea. Another cell population was exposed to TiO2 NPs under the same experimental conditions, but after treatments, cell cycle was analyzed without synchronization. Our results showed that TiO2 NP-exposed cells without synchronization had no changes in cell cycle distribution; however, cell population synchronized after 1 and 10 μg/cm(2) TiO2 NP treatment showed a 1.5-fold and 1.66-fold increase, respectively, in proliferation. Synchronized cells also reveal a faster capability of TiO2 NP-exposed cells to increase cell population in the G2/M phase in the following 9 h after synchronization. We conclude that synchronization discloses a greater percentage of cells in the G2/M phase and higher proliferation than TiO2 NP-synchronized cells.

  17. Micronucleus frequency in exfoliated buccal cells from hairdresser who expose to hair products

    Directory of Open Access Journals (Sweden)

    Koh Hui Yee

    2015-06-01

    Full Text Available Background: Hairdresser is one of the fastest growing occupations in today’s society. Hairdresser help styling, cutting, colouring, perming, curling, straightening hair and various treatment to customer. Somehow, hairdresser are constantly exposed to chemical substances such as aromatic amines, hydrogen peroxide, thioglycolic acid, formaldehyde in hair products which can cause damage to human’s genome. Micronucleus is one of the effective biomarker for processes associated with the induction of DNA damage. Purpose: The aim of this study was to determine the micronucleus frequencies in buccal mucosa epithelial cells of hairdresser who were exposed to chemical of hair products. Method: This study was conducted on twenty female subjects, who were divided into 2 groups: exposed and non-exposed (control group. All subjects recruited were working in the same beauty salon. Buccal cells were obtained from each individual by using cytobrush. The cells were stained with modified Feulgen-Ronssenback method and counting of micronucleus per 1000 cell was done under light microscope. The data were analyzed using independent t-test and one-way Anova (p<0.05. Result: The result showed a significant difference in micronucleus frequency between 2 groups. There were a significantly increase of micronucleus frequency in hairdressers and increase of  micronucleus frequency with the longer duration of exposure. Conclusion: It concluded that the chemical substances of hair products had affected the micronucleus frequency ofthe epithelial cells in buccal mucosa of hairdressers.

  18. Development of a cell-based, high-throughput screening assay for ATM kinase inhibitors.

    Science.gov (United States)

    Guo, Kexiao; Shelat, Anang A; Guy, R Kiplin; Kastan, Michael B

    2014-04-01

    The ATM (ataxia-telangiectasia, mutated) protein kinase is a major regulator of cellular responses to DNA double-strand breaks (DSBs), DNA lesions that can be caused by ionizing irradiation (IR), oxidative damage, or exposure to certain chemical agents. In response to DSBs, the ATM kinase is activated and subsequently phosphorylates numerous downstream substrates, including p53, Chk2, BRCA1, and KAP1, which affect processes such as cell cycle progression and DNA repair. Numerous studies have demonstrated that loss of ATM function results in enhanced sensitivity to ionizing irradiation in clinically relevant dose ranges, suggesting that ATM kinase is an attractive therapeutic target for enhancing tumor cell kill with radiotherapy. Previously identified small-molecule ATM kinase inhibitors, such as CP466722 and Ku55933, were identified using in vitro kinase assays carried out with recombinant ATM kinase isolated from mammalian cells. Since it has not been feasible to express full-length recombinant ATM in bacterial or baculovirus systems, a robust in vitro screening tool has been lacking. We have developed a cell-based assay that is robust, straightforward, and sensitive. Using this high-throughput assay, we screened more than 7000 compounds and discovered additional small molecules that inhibit the ATM kinase and further validated these hits by secondary assays.

  19. Host cell reactivation of uv- and X-ray-damaged herpes simplex virus by Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines

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    Henderson, E.E. (Temple Univ. School of Medicine, Philadelphia, PA); Long, W.K.

    1981-12-01

    The efficacy of using an infected centers assay, employing herpes simplex virus-infected, Epstein-Barr virus-transformed lymphoblastoid cell lines (LCLs) as components, to study host cell reactivation has been explored. Herpes simplex virus type 1 (HSV-1) was shown through the infected centers assay to have detectable but varying ability to lytically infect LCLs established from chromosomal breakage syndromes or closely related genetic disorders. The rate of HSV inactivation by ultraviolet (uv) irradiation was faster in LCLs established from Cockaynes's syndrome than in normal LCLs, and faster still in LCLs established from xeroderma pigmentosum. These results indicate that Cockayne's syndrome, while having what appears to be quantitatively normal levels of uv-induced DNA repair replication, shows decreased ability to host cell reactivated uv-damaged HSV. In direct contrast, X-irradiated HSV showed identical survival when assayed on normal LCLs or LCLs established from ataxia telangiectasia showing increased sensitivity to X irradiation as measured by colony formation. Through the infected centers assay, it has also been possible to demonstrate low levels of multiplicity reactivation of mutagen-damaged HSV in permanently proliferating LCLs.

  20. Vanillin protects human keratinocyte stem cells against ultraviolet B irradiation.

    Science.gov (United States)

    Lee, Jienny; Cho, Jae Youl; Lee, Sang Yeol; Lee, Kyung-Woo; Lee, Jongsung; Song, Jae-Young

    2014-01-01

    Ultraviolet-B (UVB) irradiation is one of major factors which induce cellular damages in the epidermis. We investigated protective effects and mechanisms of vanillin, a main constituent of vanilla beans, against UVB-induced cellular damages in keratinocyte stem cells (KSC). Here, vanillin significantly attenuated UVB irradiation-induced cytotoxicity. The vanillin effects were also demonstrated by the results of the senescence-associated β-galactosidase and alkaline comet assays. In addition, vanillin induced production of pro-inflammatory cytokines. Attempts to elucidate a possible mechanism underlying the vanillin-mediated effects revealed that vanillin significantly reduced UVB-induced phosphorylation of ataxia telangiectasia mutated (ATM), serine threonine kinase checkpoint kinase 2 (Chk2), tumor suppressor protein 53 (p53), p38/mitogen-activated protein kinase (p38), c-Jun N-terminal kinase/stress-activated protein kinase (JNK), S6 ribosomal protein (S6RP), and histone 2A family member X (H2A.X). UVB-induced activation of p53 luciferase reporter was also significantly inhibited by vanillin. In addition, while ATM inhibitor had no effect on the vanillin effects, mouse double minute 2 homolog (MDM2) inhibitor significantly attenuated suppressive effects of vanillin on UVB-induced activation of p53 reporter in KSC. Taken together, these findings suggest that vanillin protects KSC from UVB irradiation and its effects may occur through the suppression of downstream step of MDM2 in UVB irradiation-induced p53 activation.

  1. Gene expression profile in bone marrow and hematopoietic stem cells in mice exposed to inhaled benzene

    Energy Technology Data Exchange (ETDEWEB)

    Faiola, Brenda; Fuller, Elizabeth S.; Wong, Victoria A.; Recio, Leslie

    2004-05-18

    Acute myeloid leukemia and chronic lymphocytic leukemia are associated with benzene exposure. In mice, benzene induces chromosomal breaks as a primary mode of genotoxicity in the bone marrow (BM). Benzene-induced DNA lesions can lead to changes in hematopoietic stem cells (HSC) that give rise to leukemic clones. To gain insight into the mechanism of benzene-induced leukemia, we investigated the DNA damage repair and response pathways in total bone marrow and bone marrow fractions enriched for HSC from male 129/SvJ mice exposed to benzene by inhalation. Mice exposed to 100 ppm benzene for 6 h per day, 5 days per week for 2 week showed significant hematotoxicity and genotoxicity compared to air-exposed control mice. Benzene exposure did not alter the level of apoptosis in BM or the percentage of HSC in BM. RNA isolated from total BM cells and the enriched HSC fractions from benzene-exposed and air-exposed mice was used for microarray analysis and quantitative real-time RT-PCR. Interestingly, mRNA levels of DNA repair genes representing distinct repair pathways were largely unaffected by benzene exposure, whereas altered mRNA expression of various apoptosis, cell cycle, and growth control genes was observed in samples from benzene-exposed mice. Differences in gene expression profiles were observed between total BM and HSC. Notably, p21 mRNA was highly induced in BM but was not altered in HSC following benzene exposure. The gene expression pattern suggests that HSC isolated immediately following a 2 weeks exposure to 100 ppm benzene were not actively proliferating. Understanding the toxicogenomic profile of the specific target cell population involved in the development of benzene-associated diseases may lead to a better understanding of the mechanism of benzene-induced leukemia and may identify important interindividual and tissue susceptibility factors.

  2. Determining adaptive and adverse oxidative stress responses in human bronical epithelial cells exposed to zinc

    Science.gov (United States)

    Determining adaptive and adverse oxidative stress responses in human bronchial epithelial cells exposed to zincJenna M. Currier1,2, Wan-Yun Cheng1, Rory Conolly1, Brian N. Chorley1Zinc is a ubiquitous contaminant of ambient air that presents an oxidant challenge to the human lung...

  3. MDC1 directs chromosome-wide silencing of the sex chromosomes in male germ cells.

    Science.gov (United States)

    Ichijima, Yosuke; Ichijima, Misako; Lou, Zhenkun; Nussenzweig, André; Camerini-Otero, R Daniel; Chen, Junjie; Andreassen, Paul R; Namekawa, Satoshi H

    2011-05-01

    Chromosome-wide inactivation is an epigenetic signature of sex chromosomes. The mechanism by which the chromosome-wide domain is recognized and gene silencing is induced remains unclear. Here we identify an essential mechanism underlying the recognition of the chromosome-wide domain in the male germline. We show that mediator of DNA damage checkpoint 1 (MDC1), a binding partner of phosphorylated histone H2AX (γH2AX), defines the chromosome-wide domain, initiates meiotic sex chromosome inactivation (MSCI), and leads to XY body formation. Importantly, MSCI consists of two genetically separable steps. The first step is the MDC1-independent recognition of the unsynapsed axis by DNA damage response (DDR) factors such as ataxia telangiectasia and Rad3-related (ATR), TOPBP1, and γH2AX. The second step is the MDC1-dependent chromosome-wide spreading of DDR factors to the entire chromatin. Furthermore, we demonstrate that, in somatic cells, MDC1-dependent amplification of the γH2AX signal occurs following replicative stress and is associated with transcriptional silencing. We propose that a common DDR pathway underlies both MSCI and the response of somatic cells to replicative stress. These results establish that the DDR pathway centered on MDC1 triggers epigenetic silencing of sex chromosomes in germ cells.

  4. The Vitamin A Derivative All-Trans Retinoic Acid Repairs Amyloid-β-Induced Double-Strand Breaks in Neural Cells and in the Murine Neocortex.

    Science.gov (United States)

    Gruz-Gibelli, Emmanuelle; Chessel, Natacha; Allioux, Clélia; Marin, Pascale; Piotton, Françoise; Leuba, Geneviève; Herrmann, François R; Savioz, Armand

    2016-01-01

    The amyloid-β peptide or Aβ is the key player in the amyloid-cascade hypothesis of Alzheimer's disease. Aβ appears to trigger cell death but also production of double-strand breaks (DSBs) in aging and Alzheimer's disease. All-trans retinoic acid (RA), a derivative of vitamin A, was already known for its neuroprotective effects against the amyloid cascade. It diminishes, for instance, the production of Aβ peptides and their oligomerisation. In the present work we investigated the possible implication of RA receptor (RAR) in repair of Aβ-induced DSBs. We demonstrated that RA, as well as RAR agonist Am80, but not AGN 193109 antagonist, repair Aβ-induced DSBs in SH-SY5Y cells and an astrocytic cell line as well as in the murine cortical tissue of young and aged mice. The nonhomologous end joining pathway and the Ataxia Telangiectasia Mutated kinase were shown to be involved in RA-mediated DSBs repair in the SH-SY5Y cells. Our data suggest that RA, besides increasing cell viability in the cortex of young and even of aged mice, might also result in targeted DNA repair of genes important for cell or synaptic maintenance. This phenomenon would remain functional up to a point when Aβ increase and RA decrease probably lead to a pathological state.

  5. Protein C inhibitor (PCI binds to phosphatidylserine exposing cells with implications in the phagocytosis of apoptotic cells and activated platelets.

    Directory of Open Access Journals (Sweden)

    Daniela Rieger

    Full Text Available Protein C Inhibitor (PCI is a secreted serine protease inhibitor, belonging to the family of serpins. In addition to activated protein C PCI inactivates several other proteases of the coagulation and fibrinolytic systems, suggesting a regulatory role in hemostasis. Glycosaminoglycans and certain negatively charged phospholipids, like phosphatidylserine, bind to PCI and modulate its activity. Phosphatidylerine (PS is exposed on the surface of apoptotic cells and known as a phagocytosis marker. We hypothesized that PCI might bind to PS exposed on apoptotic cells and thereby influence their removal by phagocytosis. Using Jurkat T-lymphocytes and U937 myeloid cells, we show here that PCI binds to apoptotic cells to a similar extent at the same sites as Annexin V, but in a different manner as compared to live cells (defined spots on ∼10-30% of cells. PCI dose dependently decreased phagocytosis of apoptotic Jurkat cells by U937 macrophages. Moreover, the phagocytosis of PS exposing, activated platelets by human blood derived monocytes declined in the presence of PCI. In U937 cells the expression of PCI as well as the surface binding of PCI increased with time of phorbol ester treatment/macrophage differentiation. The results of this study suggest a role of PCI not only for the function and/or maturation of macrophages, but also as a negative regulator of apoptotic cell and activated platelets removal.

  6. Protein C inhibitor (PCI) binds to phosphatidylserine exposing cells with implications in the phagocytosis of apoptotic cells and activated platelets.

    Science.gov (United States)

    Rieger, Daniela; Assinger, Alice; Einfinger, Katrin; Sokolikova, Barbora; Geiger, Margarethe

    2014-01-01

    Protein C Inhibitor (PCI) is a secreted serine protease inhibitor, belonging to the family of serpins. In addition to activated protein C PCI inactivates several other proteases of the coagulation and fibrinolytic systems, suggesting a regulatory role in hemostasis. Glycosaminoglycans and certain negatively charged phospholipids, like phosphatidylserine, bind to PCI and modulate its activity. Phosphatidylerine (PS) is exposed on the surface of apoptotic cells and known as a phagocytosis marker. We hypothesized that PCI might bind to PS exposed on apoptotic cells and thereby influence their removal by phagocytosis. Using Jurkat T-lymphocytes and U937 myeloid cells, we show here that PCI binds to apoptotic cells to a similar extent at the same sites as Annexin V, but in a different manner as compared to live cells (defined spots on ∼10-30% of cells). PCI dose dependently decreased phagocytosis of apoptotic Jurkat cells by U937 macrophages. Moreover, the phagocytosis of PS exposing, activated platelets by human blood derived monocytes declined in the presence of PCI. In U937 cells the expression of PCI as well as the surface binding of PCI increased with time of phorbol ester treatment/macrophage differentiation. The results of this study suggest a role of PCI not only for the function and/or maturation of macrophages, but also as a negative regulator of apoptotic cell and activated platelets removal.

  7. α1-Antitrypsin reduces rhinovirus infection in primary human airway epithelial cells exposed to cigarette smoke

    Directory of Open Access Journals (Sweden)

    Berman R

    2016-06-01

    Full Text Available Reena Berman, Di Jiang, Qun Wu, Hong Wei Chu Department of Medicine, National Jewish Health, Denver, CO, USA Abstract: Human rhinovirus (HRV infections target airway epithelium and are the leading cause of acute exacerbations of COPD. Cigarette smoke (CS increases the severity of viral infections, but there is no effective therapy for HRV infection. We determined whether α1-antitrypsin (A1AT reduces HRV-16 infection in CS-exposed primary human airway epithelial cells. Brushed bronchial epithelial cells from normal subjects and patients diagnosed with COPD were cultured at air–liquid interface to induce mucociliary differentiation. These cells were treated with A1AT or bovine serum albumin for 2 hours and then exposed to air or whole cigarette smoke (WCS with or without HRV-16 (5×104 50% Tissue Culture Infective Dose [TCID50]/transwell infection for 24 hours. WCS exposure significantly increased viral load by an average of fivefold and decreased the expression of antiviral genes interferon-λ1, OAS1, and MX1. When A1AT was added to WCS-exposed cells, viral load significantly decreased by an average of 29-fold. HRV-16 infection significantly increased HRV-16 receptor intercellular adhesion molecule-1 messenger RNA expression in air-exposed cells, which was decreased by A1AT. A1AT-mediated reduction of viral load was not accompanied by increased epithelial antiviral gene expression or by inhibiting the activity of 3C protease involved in viral replication or maturation. Our findings demonstrate that A1AT treatment prevents a WCS-induced increase in viral load and for the first time suggest a therapeutic effect of A1AT on HRV infection. Keywords: α1-antitrypsin, rhinovirus, COPD, cigarette smoke, ICAM-1

  8. Effect of photobiomodulation on endothelial cell exposed to Bothrops jararaca venom.

    Science.gov (United States)

    Franco, Ana Tereza Barufi; Silva, Luciana Miato Gonçalves; Costa, Marcília Silva; Zamuner, Silvia Fernanda; Vieira, Rodolfo Paula; de Fatima Pereira Teixeira, Catarina; Zamuner, Stella Regina

    2016-07-01

    Bleeding is a common feature in envenoming caused by Bothrops snake venom due to extensive damage to capillaries and venules, producing alterations in capillary endothelial cell morphology. It has been demonstrated, in vivo, that photobiomodulation (PBM) decreases hemorrhage after venom inoculation; however, the mechanism is unknown. Thus, the objective was to investigate the effects of PBM on a murine endothelial cell line (tEnd) exposed to Bothrops jararaca venom (BjV). Cells were exposed to BjV and irradiated once with either 660- or 780-nm wavelength laser light at energy densities of 4 and 5 J/cm(2), respectively, and irradiation time of 10 s. Cell integrity was analyzed by crystal violet and cell viability/mitochondrial metabolism by MTT assay. The release of lactic dehydrogenase (LDH) was quantified as a measure of cell damage. In addition, cytokine IL1-β levels were measured in the supernatant. PBM at 660 and 780 nm wavelength was able to increase cellular viability and decrease the release of LDH and the loss of cellular integrity. In addition, the concentration of pro-inflammatory cytokine IL1-β was reduced after PBM by both wavelengths. The data reported herein indicates that irradiation with red or near-infrared laser resulted in protection on endothelial cells after exposure to Bothrops venom and could be, at least in part, a reasonable explanation by the beneficial effects of PBM inhibiting the local effects induced by Bothrops venoms, in vivo.

  9. Cultured skin keratinocytes from both normal individuals and basal cell naevus syndrome patients are more resistant to. gamma. -rays and UV light compared with cultured skin fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Stacey, M.; Thacker, S.; Taylor, A.M.R. (Birmingham Univ. (UK). Cancer Research Campaign Labs.)

    1989-07-01

    Measurement of colony-forming ability following exposure to {gamma}-rays was performed on cultured skin keratinocytes and skin fibroblasts from normal individuals, basal cell naevus syndrome patients (BCNS) and ataxia telangiectasia (A-T) patients. The most striking observation was the radiation resistance of 8/8 keratinocyte strains compared with fibroblasts whether from BCNS patients or normals. The single A-T keratinocyte cell strain showed the same radiosensitivity as A-T fibroblast cell strains. The differential survival of keratinocytes and fibroblasts was also observed following exposure to 254 nm UV light. Survival curves of SV40 immortalized keratinocytes and retinoblasts derived from normal individuals or BCNS patients showed large shoulder regions following exposure to {gamma}-rays or 254 nm UV light. An increased D{sub 37} rather than an increased D{sub o} was therefore the feature of such curves, contrasting with SV40 immortalized A-T keratinocytes or fibroblasts which showed a minimal shoulder effect and an increased D{sub o}. No difference in survival was observed between BCNS and normal cells following exposure to either UV or {gamma}-rays. (author).

  10. Endometrial stem cell transplantation in MPTP- exposed primates: an alternative cell source for treatment of Parkinson's disease.

    Science.gov (United States)

    Wolff, Erin F; Mutlu, Levent; Massasa, Efi E; Elsworth, John D; Eugene Redmond, D; Taylor, Hugh S

    2015-01-01

    Parkinson's disease (PD) is a neurodegenerative disease caused by the loss of dopaminergic neurons in the substantia nigra. Cell-replacement therapies have emerged as a promising strategy to slow down or replace neuronal loss. Compared to other stem cell types, endometrium-derived stem cells (EDSCs) are an attractive source of stem cells for cellular therapies because of their ease of collection and vast differentiation potential. Here we demonstrate that endometrium-derived stem cells may be transplanted into an MPTP exposed monkey model of PD. After injection into the striatum, endometrium-derived stem cells engrafted, exhibited neuron-like morphology, expressed tyrosine hydroxylase (TH) and increased the numbers of TH positive cells on the transplanted side and dopamine metabolite concentrations in vivo. Our results suggest that endometrium-derived stem cells may provide a therapeutic benefit in the primate model of PD and may be used in stem cell based therapies.

  11. Noise induced calcium oscillations in a cell exposed to electromagnetic fields.

    Science.gov (United States)

    Zhang, Yuhong; Zhao, Yongli; Chen, Yafei; Yuan, Changqing; Zhan, Yong

    2015-01-01

    The effects of noise on the calcium oscillations in a cell exposed to electromagnetic fields are described by a dynamic model. Noise is a very important factor to be considered in the dynamic research on the calcium oscillations in a cell exposed to electromagnetic fields. Some meaningful results have been obtained here based on the discussion. The results show that the pattern of intracellular calcium oscillations exposure to electromagnetic fields can be influenced by noise. Furthermore, the intracellular calcium oscillations exposure to electromagnetic fields can also be induced by noise. And the work has also studied the relationships between the voltage sensitive calcium channel's open probability and electromagnetic field. The result can provide new insights into constructive roles and potential applications of selecting appropriate electromagnetic field frequency during the research of biological effect of electromagnetic field.

  12. Mutagenicity and genotoxicity in gill erythrocyte cells of Poecilia reticulata exposed to a glyphosate formulation.

    Science.gov (United States)

    De Souza Filho, José; Sousa, Caio César Neves; Da Silva, Cláudio Carlos; De Sabóia-Morais, Simone Maria Teixeira; Grisolia, Cesar Koppe

    2013-11-01

    Poecilia reticulata were exposed to herbicide Roundup Transorb(®) for micronucleus test, nuclear abnormalities and comet assay. The exposure-concentrations were based on CL50-96 h following 0, 1.41, 2.83, 4.24 and 5.65 μL L(-1) for 24 h. Micronucleus and comets were significantly increased in the gill erythrocyte cells after herbicide exposure compared with the non-exposed group. Results showed a gradual increase in the number of damaged cells, indicating a concentration-dependent effect and that this herbicide was mutagenic and genotoxic to P. reticulata and this effect could be attributed to a combination of compounds contained in the formulation with the active ingredient glyphosate.

  13. DNA damage in leukocytes, buccal cells and nasal epithelial cells of individuals exposed to air pollution in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Valverde, M.; Lopez, M.C.; Ostrosky-Wegman, P. [and others

    1997-10-01

    There is an increased interest in using biological markers to monitor populations for the identification of exposure to environmental toxicants. Test systems which permit the sensitive detection of DNA damage and DNA repair are critically important. The single cell gel electrophoresis assay is a rapid and a sensitive method for the evaluation of DNA damage at the single cell level ant it provides information on the occurrence of DNA single-strand breaks and alkali labile sites using alkaline conditions. In this work, the differences in the basal level of DNA single strand breaks using alkaline single strand breaks using alkaline single cell gel electrophoresis, between young adults from the south (exposed principally to high levels of ozone) and north (exposed principally to hydrocarbons and particles) of Mexico City was investigated using three different cell types (leukocytes, nasal and buccal epithelial cells). We found an increased DNA tail length in blood and nasal cells from individuals who live in the south part of the city compared to the northern part. However, no differences were observed in buccal epithelial cells. These results show the feasibility of using SCGE in different tissues and its great potential for the monitoring of humans exposed to xenobiotics.

  14. Natural killer cells in highly exposed hepatitis C-seronegative injecting drug users.

    Science.gov (United States)

    Mina, M M; Cameron, B; Luciani, F; Vollmer-Conna, U; Lloyd, A R

    2016-06-01

    Injecting drug use remains the major risk factor for hepatitis C (HCV) transmission. A minority of long-term injecting drug users remain seronegative and aviraemic, despite prolonged exposure to HCV - termed highly exposed seronegative subjects. Natural killer (NK) cells have been implicated in this apparent protection. A longitudinal nested, three group case-control series of subjects was selected from a prospective cohort of seronegative injecting drug users who became incident cases (n = 11), remained seronegative (n = 11) or reported transient high-risk behaviour and remained uninfected (n = 11). The groups were matched by age, sex and initial risk behaviour characteristics. Stored peripheral blood mononuclear cells were assayed in multicolour flow cytometry to enumerate natural killer cell subpopulations and to assess functional activity using Toll-like receptor ligands before measurement of activation, cytokine production and natural cytotoxicity receptor expression. Principal components were derived to describe the detailed phenotypic characteristics of the major NK subpopulations (based on CD56 and CD16 co-expression), before logistic regression analysis to identify associations with exposed, seronegative individuals. The CD56(dim) CD16(+) (P = 0.05, OR 6.92) and CD56(dim) CD16(-) (P = 0.05, OR 6.07) principal components differed between exposed, seronegative individuals and pre-infection samples of the other two groups. These included CD56(dim) CD16(+) and CD56(dim) CD16(-) subsets with CD56(dim) CD16(+) IFN-γ and TNF-α on unstimulated cells, and CD56(dim) CD16(-) CD69(+) , CD107a(+) , IFN-γ and TNF-α following TLR stimulation. The cytotoxic CD56(dim) NK subset thus distinguished highly exposed, seronegative subjects, suggesting NK cytotoxicity may contribute to protection from HCV acquisition. Further investigation of the determinants of this association and prospective assessment of protection against HCV infection are warranted.

  15. Antioxidative capacity and enzyme activity in Haematococcus pluvialis cells exposed to superoxide free radicals

    Institute of Scientific and Technical Information of China (English)

    刘建国; 张晓丽; 孙延红; 林伟

    2010-01-01

    The antioxidative capacity of astaxanthin and enzyme activity of reactive oxygen eliminating enzymes such as superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX) were studied in three cell types of Haematococcus pluvialis exposed to high concentrations of a superoxide anion radical (O2ˉ).The results show that defensive enzymes and astaxanthin-related mechanisms were both active in H.pluvialis during exposure to reactive oxygen species (ROS) such as Oˉ2.Astaxanthin reacte...

  16. Apoptosis and necroptosis are induced in rainbow trout cell lines exposed to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Krumschnabel, Gerhard, E-mail: Gerhard.Krumschnabel@i-med.ac.at [Division of Developmental Immunology, Biocenter, Medical University Innsbruck, Fritz-Preglstr. 3, Innsbruck (Austria); Ebner, Hannes L.; Hess, Michael W. [Division of Histology and Embryology, Medical University Innsbruck, Innsbruck (Austria); Villunger, Andreas [Division of Developmental Immunology, Biocenter, Medical University Innsbruck, Fritz-Preglstr. 3, Innsbruck (Austria)

    2010-08-01

    Cadmium is an important environmental toxicant that can kill cells. A number of studies have implicated apoptosis as well as necrosis and, most recently, a form of programmed necrosis termed necroptosis in the process of cadmium-mediated toxicity, but the exact mechanism remains ill-defined and may depend on the affected cell type. This study investigated which mode of cell death may be responsible for cell death induction in cadmium-exposed trout cell lines from gill and liver and if this cell death was sensitive to inhibitors of necroptosis or apoptosis, respectively. It was observed that intermediate levels of cadmium that killed approximately 50% of the cells over 96-120 h of exposure caused cell death that morphologically resembled apoptosis and was associated with an increase of apoptotic markers such as the number of cells with diminished DNA content (sub-G1 cells), condensed or fragmented nuclei, and elevation of caspase-3 activity. At the same time, however, cells also lost plasma membrane integrity, as indicated by uptake of propidium iodide, showed a decrease of ATP levels and mitochondrial membrane potential, and displayed cell swelling, signs associated with secondary necrosis, or equally possible, necroptotic cell death. Importantly, many of these alterations were at least partly inhibited by the necroptosis inhibitor necrostatin-1 and were to a lesser extent also sensitive to the pan-caspase inhibitor zVAD-fmk, indicating that multiple modes of cell death are concurrently induced in cadmium-exposed trout cells, including necroptosis and apoptosis. Cell death appeared to lack concurrent radical formation, consistent with genetically regulated necroptotic cell death, but was characterized by the rapid induction of DNA damage markers, and the early onset of disintegration of the Golgi complex. Comparative experiments evaluating copper-toxicity indicated that in comparison to cadmium much higher concentrations of this metal were required to induce cell

  17. Diagnostic and pathogenetic role of café-au-lait macules in nevoid basal cell carcinoma syndrome

    Directory of Open Access Journals (Sweden)

    Ponti Giovanni

    2012-10-01

    Full Text Available Abstract Café au lait spots (CALS are common dermatologic findings that can at the same time arise in a variety of pathologic conditions such as Neurofibromatosis type 1 (NF1, together with numerous hereditary syndromes for which they represent either diagnostic criteria or associated elements (McCune Albright, Silver-Russell, LEOPARD, Ataxia-Telangiectasia. A review of the literature also revealed two cases of association with NBCCS. We report here the case of a female proband with CALS associated to Nevoid Basal Cell Carcinoma Syndrome (NBCCS with known PTCH1 germline mutation (C.1348-2A>G who had been misdiagnosed with NF1 in her childhood because of 5 CALS and cutaneous nodules. The patient presented a giant cell tumor of the skin, palmar and calcaneal epidermoidal cystic nodules, odontogenic keratocystic tumors and deformity of the jaw profile. Her family history brought both her brother and father to our attention because of the presence of KCOTs diagnosed at early age: after genetic testing, the same PTCH1 germline mutation was identified in the three family members. Clinical criteria are used for discerning NF1 diagnosis (size, number and onset age, while there are no definite guidelines concerning CALS except for their presence. In our experience, we have noted an association of CALS with NBCCS; this seems interesting because we already know clinical criteria are a dynamic entity and can be modified by epidemiologic evidences.

  18. Frequency patterns of T-cell exposed motifs in immunoglobulin heavy chain peptides presented by MHCs

    Directory of Open Access Journals (Sweden)

    Robert D. Bremel

    2014-10-01

    Full Text Available Immunoglobulins are highly diverse protein sequences that are processed and presented to T-cells by B-cells and other antigen presenting cells. We examined a large dataset of immunoglobulin heavy chain variable regions (IGHV to assess the diversity of T-cell exposed motifs (TCEM. TCEM comprise those amino acids in a MHC-bound peptide which face outwards, surrounded by the MHC histotope, and which engage the T-cell receptor. Within IGHV there is a distinct pattern of predicted MHC class II binding and a very high frequency of re-use of the TCEMs. The re-use frequency indicates that only a limited number of different cognate T-cells are required to engage many different clonal B-cells. The amino acids in each outward-facing TCEM are intercalated with the amino acids of inward-facing MHC groove-exposed motifs (GEM. Different GEM may have differing, allele-specific, MHC binding affinities. The intercalation of TCEM and GEM in a peptide allows for a vast combinatorial repertoire of epitopes, each eliciting a different response. Outcome of T-cell receptor binding is determined by overall signal strength, which is a function of the number of responding T-cells and the duration of engagement. Hence, the frequency of T-cell exposed motif re-use appears to be an important determinant of whether a T-cell response is stimulatory or suppressive. The frequency distribution of TCEMs implies that somatic hypermutation is followed by clonal expansion that develop along repeated pathways. The observations of TCEM and GEM derived from immunoglobulins suggest a relatively simple, yet powerful, mechanism to correlate T-cell polyspecificity, through re-use of TCEMs, with a very high degree of specificity achieved by combination with a diversity of GEMs. The frequency profile of TCEMs also points to an economical mechanism for maintaining T-cell memory, recall, and self-discrimination based on an endogenously generated profile of motifs.

  19. Reduced cytotoxicity in PCB-exposed Chinese Hamster Ovary (CHO) cells pretreated with vitamin E.

    Science.gov (United States)

    Murati, Teuta; Šimić, Branimir; Pleadin, Jelka; Vukmirović, Maja; Miletić, Marina; Durgo, Ksenija; Kniewald, Jasna; Kmetič, Ivana

    2017-01-01

    The aim of this study was to evaluate protective effects of vitamin E (50 -150 μM) in ovary cells upon cytotoxic effects induced by two structurally distinct PCB congeners - planar "dioxin-like" PCB 77 and non-planar di-ortho-substituted PCB 153 with an emphasis on identifying differences in the mechanism of vitamin E action depending on the structure of congeners. Application of three bioassays confirmed that PCBs decrease ovarian cell proliferation with slightly profound effects of PCB 77. PCB - induced ROS production and lipid peroxidation were significant for both congeners with also more noticeable effect for PCB 77. Vitamin E pre-incubation has improved viability of cells, reduced ROS formation and lipid peroxidation induced by PCBs' treatment. Preincubation with vitamin E was more effective when cells where treated with non-planar PCB 153. Altogether, vitamin E action was protective, congener specific and more effective when ovary cells were exposed to ortho-substituted PCB congener.

  20. The orally active and bioavailable ATR kinase inhibitor AZD6738 potentiates the anti-tumor effects of cisplatin to resolve ATM-deficient non-small cell lung cancer in vivo.

    Science.gov (United States)

    Vendetti, Frank P; Lau, Alan; Schamus, Sandra; Conrads, Thomas P; O'Connor, Mark J; Bakkenist, Christopher J

    2015-12-29

    ATR and ATM are DNA damage signaling kinases that phosphorylate several thousand substrates. ATR kinase activity is increased at damaged replication forks and resected DNA double-strand breaks (DSBs). ATM kinase activity is increased at DSBs. ATM has been widely studied since ataxia telangiectasia individuals who express no ATM protein are the most radiosensitive patients identified. Since ATM is not an essential protein, it is widely believed that ATM kinase inhibitors will be well-tolerated in the clinic. ATR has been widely studied, but advances have been complicated by the finding that ATR is an essential protein and it is widely believed that ATR kinase inhibitors will be toxic in the clinic. We describe AZD6738, an orally active and bioavailable ATR kinase inhibitor. AZD6738 induces cell death and senescence in non-small cell lung cancer (NSCLC) cell lines. AZD6738 potentiates the cytotoxicity of cisplatin and gemcitabine in NSCLC cell lines with intact ATM kinase signaling, and potently synergizes with cisplatin in ATM-deficient NSCLC cells. In contrast to expectations, daily administration of AZD6738 and ATR kinase inhibition for 14 consecutive days is tolerated in mice and enhances the therapeutic efficacy of cisplatin in xenograft models. Remarkably, the combination of cisplatin and AZD6738 resolves ATM-deficient lung cancer xenografts.

  1. Inducible expression of beta defensins by human respiratory epithelial cells exposed to Aspergillus fumigatus organisms

    Directory of Open Access Journals (Sweden)

    Tichanné-Seltzer Virginie

    2009-02-01

    Full Text Available Abstract Background Aspergillus fumigatus, a saprophytic mould, is responsible for life-threatening, invasive pulmonary diseases in immunocompromised hosts. The role of the airway epithelium involves a complex interaction with the inhaled pathogen. Antimicrobial peptides with direct antifungal and chemotactic activities may boost antifungal immune response. Results The inducible expression of defensins by human bronchial epithelial 16HBE cells and A549 pneumocyte cells exposed to A. fumigatus was investigated. Using RT-PCR and real time PCR, we showed an activation of hBD2 and hBD9 defensin genes: the expression was higher in cells exposed to swollen conidia (SC, compared to resting conidia (RC or hyphal fragments (HF. The kinetics of defensin expression was different for each one, evoking a putative distinct function for each investigated defensin. The decrease of defensin expression in the presence of heat-inactivated serum indicated a possible link between defensins and the proteins of the host complement system. The presence of defensin peptide hBD2 was revealed using immunofluorescence that showed a punctual cytoplasmic and perinuclear staining. Quantification of the cells stained with anti hBD2 antibody demonstrated that SC induced a greater number of cells that synthesized hBD2, compared to RC or HF. Labelling of the cells with anti-hBD-2 antibody showed a positive immunofluorescence signal around RC or SC in contrast to HF. This suggests co-localisation of hBD2 and digested conidia. The HBD2 level was highest in the supernatants of cells exposed to SC, as was determined by sandwich ELISA. Experiments using neutralising anti-interleukine-1β antibody reflect the autocrine mechanism of defensin expression induced by SC. Investigation of defensin expression at transcriptional and post-transcriptional levels demonstrated the requirement of transcription as well as new protein synthesis during A. fumigatus defensin induction. Finally, induced

  2. Protective Effects of Hydroalcoholic Extract of Nasturtium officinale on Rat Blood Cells Exposed to Arsenic

    Directory of Open Access Journals (Sweden)

    Felor Zargari

    2015-06-01

    Full Text Available Background: Arsenic is one of the most toxic metalloids. Anemia and leukopenia are common results of poisoning with arsenic, which may happen due to a direct hemolytic or cytotoxic effect on blood cells. The aim of this study was to examine the effects of hydroalcoholic extract of Nasturtium officinale on blood cells and antioxidant enzymes in rats exposed to sodium (metaarsenite. Methods: 32 Male Sprague Dawley rats were randomly divided into four groups; Group I (normal healthy rats, Group II (treated with 5.5mg/kg of body weight of NaAsO2, Group III (treated with 500mg/kg of body weight of hydro-alcoholic extract of N. officinale, and Group IV (treated with group II and III supplementations. Blood samples were collected and red blood cell, white blood cell, hematocrit, hemoglobin, platelet, total protein and albumin levels and total antioxidant capacity were measured. Data was analyzed with Mann-Whitney U test. Results: WBC, RBC and Hct were decreased in the rats exposed to NaAsO2 (p<0.05. A significant increase was seen in RBC and Hct after treatment with the plant extract (p<0.05. There was no significant decrease in serum albumin and total protein in the groups exposed to NaAsO2 compared to the group I, but NaAsO2 decreased the total antioxidant capacity, significantly. Conclusion: The Nasturtium officinale extract have protective effect on arsenic-induced damage of blood cells.

  3. Cell surface differences of Naegleria fowleri and Naegleria lovaniensis exposed with surface markers.

    Science.gov (United States)

    González-Robles, Arturo; Castañón, Guadalupe; Cristóbal-Ramos, Ana Ruth; Hernández-Ramírez, Verónica Ivonne; Omaña-Molina, Maritza; Martínez-Palomo, Adolfo

    2007-12-01

    Differences in the distribution of diverse cell surface coat markers were found between Naegleria fowleri and Naegleria lovaniensis. The presence of carbohydrate-containing components in the cell coat of the two species was detected by selective staining with ruthenium red and alcian blue. Using both markers, N. fowleri presented a thicker deposit than N. lovaniensis. The existence of exposed mannose or glucose residues was revealed by discriminatory agglutination with the plant lectin Concanavalin A. These sugar residues were also visualized at the cell surface of these parasites either by transmission electron microscopy or by fluorescein-tagged Concanavalin A. Using this lectin cap formation was induced only in N. fowleri. The anionic sites on the cell surface detected by means of cationized ferritin were more apparent in N. fowleri. Biotinylation assays confirmed that even though the two amoebae species have some analogous plasma membrane proteins, there is a clear difference in their composition.

  4. Assessment of DNA integrity (COMET assay) in sperm cells of boron-exposed workers.

    Science.gov (United States)

    Duydu, Yalçin; Başaran, Nurşen; Ustündağ, Aylin; Aydin, Sevtap; Undeğer, Ulkü; Ataman, Osman Yavuz; Aydos, Kaan; Düker, Yalçin; Ickstadt, Katja; Waltrup, Britta Schulze; Golka, Klaus; Bolt, Hermann M

    2012-01-01

    An extension of a male reproductive study conducted in a boric acid/borate production zone at Bandırma, Turkey, is presented. The relation between DNA-strand breaks (COMET assay, neutral and alkaline version) in sperm cells and previously described sperm quality parameters was investigated in boron-exposed males. A correlation between blood boron levels and mean DNA-strand breaks in sperm was weak, and DNA-strand breaks in sperm were statistically not different between control and exposed groups. Therefore, increasing boron exposures had no additional contribution in addition to already pre-existing DNA-strand breaks in the sperm cells. Weak but statistically significant correlations between DNA-strand breaks and motility/morphology parameters of sperm samples were observed in the neutral version of the COMET assay, while correlations between the same variables were statistically not significant in the alkaline version. A likely reason for these negative results, even in highly exposed humans, is that experimental exposures that had led to reproductive toxicity in animals were significantly higher than any boron exposures, which may be reached under realistic human conditions.

  5. Dose- and Time-Dependent Transcriptional Response of Ishikawa Cells Exposed to Genistein.

    Science.gov (United States)

    Naciff, Jorge M; Khambatta, Zubin S; Carr, Gregory J; Tiesman, Jay P; Singleton, David W; Khan, Sohaib A; Daston, George P

    2016-05-01

    To further define the utility of the Ishikawa cells as a reliable in vitro model to determine the potential estrogenic activity of chemicals of interest, transcriptional changes induced by genistein (GES) in Ishikawa cells at various doses (10 pM, 1 nM, 100 nM, and 10 μM) and time points (8, 24, and 48 h) were identified using a comprehensive microarray approach. Trend analysis indicated that the expression of 5342 unique genes was modified by GES in a dose- and time-dependent manner (P ≤ 0.0001). However, the majority of gene expression changes induced in Ishikawa cells were elicited by the highest dose of GES evaluated (10 μM). The GES' estrogenic activity was identified by comparing the Ishikawa cells' response to GES versus 17 α-ethynyl estradiol (EE, at equipotent doses, ie, 10 μM vs 1 μM, respectively) and was defined by changes in the expression of 284 unique genes elicited by GES and EE in the same direction, although the magnitude of the change for some genes was different. Further, comparing the response of the Ishikawa cells exposed to high doses of GES and EE versus the response of the juvenile rat uterus exposed to EE, we identified 66 unique genes which were up- or down regulated in a similar manner in vivo as well as in vitro Genistein elicits changes in multiple molecular pathways affecting various biological processes particularly associated with cell organization and biogenesis, regulation of translation, cell proliferation, and intracellular transport; processes also affected by estrogen exposure in the uterus of the rat. These results indicate that Ishikawa cells are capable of generating a biologically relevant estrogenic response and offer an in vitro model to assess this mode of action.

  6. Dynamic changes of [Ca2+]i in cerebellar granule cells exposed to pulsed electric fields

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Intracellular free Ca2+ concentration ([Ca2+]i) in embryonic chick cerebellar granule cells loaded with fluo-3/AM and exposed to a single pulsed electric field was investigated using a confocal laser scanning microscope and fluorescent microscope equipped with CCD video imaging system.The results showed that [Ca2+]i increased immediately and rose to the peak rapidly as the cells exposed to a single pulsed electric field.The amplitude and rate of the increases of [Ca2+]i depend on the intensity of external electric field.In the presence of Ca2+ chelant EGTA or Ca2+ channels blocker La3+ in the pulsation solutions,the increase of [Ca2+]i was still observable.It was also observed that [Ca2+]i of different intracellular areas in the cell elevated simultaneously while the peak of the increase of [Ca2+]i in the poles of the cell preceded to the peak in its somata and recovered to a plateau within a short time.

  7. Dynamic changes of [Ca2+]i in cerebellar granule cells exposed to pulsed electric fields

    Institute of Scientific and Technical Information of China (English)

    陈雅; 王彦; 孙彤; 张锦珠; 景向红; 李瑞午

    2000-01-01

    Intracellular free Ca2+ concentration ([Ca2+]i) in embryonic chick cerebellar granule cells loaded with fluo-3/AM and exposed to a single pulsed electric field was investigated using a confocal laser scanning microscope and fluorescent microscope equipped with CCD video imaging system. The results showed that [Ca2+]i increased immediately and rose to the peak rapidly as the cells exposed to a single pulsed electric field. The amplitude and rate of the increases of [Ca2+]i depend on the intensity of external electric field. In the presence of Ca2+ chelant EGTA or Ca2+ channels blocker La3+ in the pulsation solutions, the increase of [Ca2+]i was still observable. It was also observed that [Ca2+]i of different intracellular areas in the cell elevated simultaneously while the peak of the increase of [Ca2+]i in the poles of the cell preceded to the peak in its somata and recovered to a plateau within a short time.

  8. Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells

    Science.gov (United States)

    Yuan, Hengguang; Hu, Shanglian; Huang, Peng; Song, Hua; Wang, Kan; Ruan, Jing; He, Rong; Cui, Daxiang

    2011-12-01

    Herein we are the first to report that single-walled carbon nanotubes (SWCNTs) exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS) generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis.

  9. Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells

    Directory of Open Access Journals (Sweden)

    Huang Peng

    2011-01-01

    Full Text Available Abstract Herein we are the first to report that single-walled carbon nanotubes (SWCNTs exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis.

  10. Radioprotection and Cell Cycle Arrest of Intestinal Epithelial Cells by Darinaparsin, a Tumor Radiosensitizer

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Junqiang; Doi, Hiroshi [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California (United States); Saar, Matthias; Santos, Jennifer [Department of Urology, School of Medicine, Stanford University, Stanford, California (United States); Li, Xuejun; Peehl, Donna M. [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California (United States); Knox, Susan J., E-mail: sknox@stanford.edu [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California (United States)

    2013-12-01

    Purpose: It was recently reported that the organic arsenic compound darinaparsin (DPS) is a cytotoxin and radiosensitizer of tumor cells in vitro and in subcutaneous xenograft tumors. Surprisingly, it was also found that DPS protects normal intestinal crypt epithelial cells (CECs) from clonogenic death after ionizing radiation (IR). Here we tested the DPS radiosensitizing effect in a clinically relevant model of prostate cancer and explored the radioprotective effect and mechanism of DPS on CECs. Methods and Materials: The radiation modification effect of DPS was tested in a mouse model of orthotopic xenograft prostate cancer and of IR-induced acute gastrointestinal syndrome. The effect of DPS on CEC DNA damage and DNA damage responses was determined by immunohistochemistry. Results: In the mouse model of IR-induced gastrointestinal syndrome, DPS treatment before IR accelerated recovery from body weight loss and increased animal survival. DPS decreased post-IR DNA damage and cell death, suggesting that the radioprotective effect was mediated by enhanced DNA damage repair. Shortly after DPS injection, significant cell cycle arrest was observed in CECs at both G1/S and G2/M checkpoints, which was accompanied by the activation of cell cycle inhibitors p21 and growth arrest and DNA-damage-inducible protein 45 alpha (GADD45A). Further investigation revealed that DPS activated ataxia telangiectasia mutated (ATM), an important inducer of DNA damage repair and cell cycle arrest. Conclusions: DPS selectively radioprotected normal intestinal CECs and sensitized prostate cancer cells in a clinically relevant model. This effect may be, at least in part, mediated by DNA damage response activation and has the potential to significantly increase the therapeutic index of radiation therapy.

  11. Live-cell imaging study of mitochondrial morphology in mammalian cells exposed to X-rays.

    Science.gov (United States)

    Noguchi, M; Kanari, Y; Yokoya, A; Narita, A; Fujii, K

    2015-09-01

    Morphological changes in mitochondria induced by X-irradiation in normal murine mammary gland cells were studied with a live-cell microscopic imaging technique. Mitochondria were visualised by staining with a specific fluorescent probe in the cells, which express fluorescent ubiquitination-based cell-cycle indicator 2 (Fucci2) probes to visualise cell cycle. In unirradiated cells, the number of cells with fragmented mitochondria was about 20 % of the total cells through observation period (96 h). In irradiated cells, the population with fragmented mitochondria significantly increased depending on the absorbed dose. Particularly, for 8 Gy irradiation, the accumulation of fragmentation persists even in the cells whose cell cycle came to a stand (80 % in G1 (G0-like) phase). The fraction reached to a maximum at 96 h after irradiation. The kinetics of the fraction with fragmented mitochondria was similar to that for cells in S/G2/M phase (20 %) through the observation period (120 h). The evidences show that, in irradiated cells, some signals are continually released from a nucleus or cytoplasm even in the G0-like cells to operate some sort of protein machineries involved in mitochondrial fission. It is inferred that this delayed mitochondrial fragmentation is strongly related to their dysfunction, and hence might modulate radiobiological effects such as mutation or cell death.

  12. Regulation of gene expression in Dictyostelium discoideum cells exposed to immobilized carbohydrates.

    Science.gov (United States)

    Bozzaro, S; Perlo, C; Ceccarelli, A; Mangiarotti, G

    1984-01-01

    When amoebae of Dictyostelium discoideum develop on gels of polyacrylamide that are derivatized with glucosides, they become capable of aggregation at the same time as cells not exposed to glucosides. However, the aggregation centers and streams of adherent cells formed on immobilized glucosides suddenly disintegrate. The cells repeatedly re-aggregate, but never form tight aggregates as they do on other substrata. Tight aggregates formed in the absence of glucosides disperse after their transfer to glucoside gels, and the cells undergo aggregation-disaggregation cycles. The formation of tight aggregates is correlated with the expression of specific post-aggregative poly(A) RNAs. These RNAs are not expressed in cells developing on glucoside gels, and the dispersal of tight aggregates on such gels is accompanied by the almost complete loss of these RNAs. A developmentally regulated membrane glycoprotein called contact site A, which is a marker of aggregation-competent cells, is normally expressed on glucoside gels. Cyclic AMP is also produced, indicating that the strong increase of adenylate cyclase activity during the preaggregation phase is not affected. In conclusion, cell contact with immobilized glucosides specifically inhibits postaggregative gene expression and arrests development at the aggregation stage.

  13. Fate of D3 mouse embryonic stem cells exposed to X-rays or carbon ions.

    Science.gov (United States)

    Luft, S; Pignalosa, D; Nasonova, E; Arrizabalaga, O; Helm, A; Durante, M; Ritter, S

    2014-01-15

    The risk of radiation exposure during embryonic development is still a major problem in radiotoxicology. In this study we investigated the response of the murine embryonic stem cell (mESC) line D3 to two radiation qualities: sparsely ionizing X-rays and densely ionizing carbon ions. We analyzed clonogenic cell survival, proliferation, induction of chromosome aberrations as well as the capability of cells to differentiate to beating cardiomyocytes up to 3 days after exposure. Our results show that, for all endpoints investigated, carbon ions are more effective than X-rays at the same radiation dose. Additionally, in long term studies (≥8 days post-irradiation) chromosomal damage and the pluripotency state were investigated. These studies reveal that pluripotency markers are present in the progeny of cells surviving the exposure to both radiation types. However, only in the progeny of X-ray exposed cells the aberration frequency was comparable to that of the control population, while the progeny of carbon ion irradiated cells harbored significantly more aberrations than the control, generally translocations. We conclude that cells surviving the radiation exposure maintain pluripotency but may carry stable chromosomal rearrangements after densely ionizing radiation.

  14. Comparison between half-cell potential of reinforced concrete exposed to carbon dioxide and chloride environment

    Directory of Open Access Journals (Sweden)

    Somnuk Tangtermsirikul

    2010-10-01

    Full Text Available The objective of this study is to investigate the effect of concrete mix proportion and fly ash on half-cell potential (HCPand corrosion current density (icorr of steel in concrete exposed to different environments. Reinforced concrete specimenswith different fly ash replacement percentages and water to binder ratios (w/b were studied in this paper. The specimenswere subjected to two highly corrosive environments which are chloride and carbon dioxide. HCP and icorr were used tomonitor the corrosion process. Results of this study demonstrate that both HCP and icorr indicated the same tendency,especially for corroded specimens after being exposed to chloride. This means that HCP can be used to inspect corrosion ofsteel due to chloride. In case of carbonation, concrete specimens with fly ash showed more negative potential values thanconcrete without fly ash. However, chloride exposure test exhibited that specimen with higher fly ash replacement corrodedearlier. Moreover, HCP measurement presented different values between concrete exposed to chloride and carbon dioxide.There was an effect of carbonation to increase HCP during the initiation stage. A proper evaluation guideline for steelcorrosion due to carbonation needs to be further studied.

  15. Effects of Potassium Currents upon Action Potential of Cardiac Cells Exposed to External Electric fields

    Institute of Scientific and Technical Information of China (English)

    An-Ying Zhang; Xiao-Feng Pang

    2008-01-01

    Previous studies show that exposure to high-voltage electric fields would influence the electro cardiogram both in experimental animate and human beings. The effects of the external electric fields upon action potential of cardiac cells are studied in this paper based on the dynamical model, LR91. Fourth order Runger-Kuta is used to analyze the change of potassium ion channels exposed to external electric fields in detail. Results indicate that external electric fields could influence the current of potassium ion by adding an induced component voltage on membrane. This phenomenon might be one of the reasons of heart rate anomaly under the high-voltage electric fields.

  16. Comet-FISH with strand-specific probes reveals transcription-coupled repair of 8-oxoGuanine in human cells.

    Science.gov (United States)

    Guo, Jia; Hanawalt, Philip C; Spivak, Graciela

    2013-09-01

    Oxidized bases in DNA have been implicated in cancer, aging and neurodegenerative disease. We have developed an approach combining single-cell gel electrophoresis (comet) with fluorescence in situ hybridization (FISH) that enables the comparative quantification of low, physiologically relevant levels of DNA lesions in the respective strands of defined nucleotide sequences and in the genome overall. We have synthesized single-stranded probes targeting the termini of DNA segments of interest using a polymerase chain reaction-based method. These probes facilitate detection of damage at the single-molecule level, as the lesions are converted to DNA strand breaks by lesion-specific endonucleases or glycosylases. To validate our method, we have documented transcription-coupled repair of cyclobutane pyrimidine dimers in the ataxia telangiectasia-mutated (ATM) gene in human fibroblasts irradiated with 254 nm ultraviolet at 0.1 J/m2, a dose ∼100-fold lower than those typically used. The high specificity and sensitivity of our approach revealed that 7,8-dihydro-8-oxoguanine (8-oxoG) at an incidence of approximately three lesions per megabase is preferentially repaired in the transcribed strand of the ATM gene. We have also demonstrated that the hOGG1, XPA, CSB and UVSSA proteins, as well as actively elongating RNA polymerase II, are required for this process, suggesting cross-talk between DNA repair pathways.

  17. ER-Dependent Ca++-mediated Cytosolic ROS as an Effector for Induction of Mitochondrial Apoptotic and ATM-JNK Signal Pathways in Gallic Acid-treated Human Oral Cancer Cells.

    Science.gov (United States)

    Lu, Yao-Cheng; Lin, Meng-Liang; Su, Hong-Lin; Chen, Shih-Shun

    2016-02-01

    Release of calcium (Ca(++)) from the endoplasmic reticulum (ER) has been proposed to be involved in induction of apoptosis by oxidative stress. Using inhibitor of ER Ca(++) release dantrolene and inhibitor of mitochondrial Ca(++) uptake Ru-360, we demonstrated that Ca(++) release from the ER was associated with generation of reactive oxygen species (ROS), loss of mitochondrial membrane potential, and apoptosis of human oral cancer (OC) cells induced by gallic acid (GA). Small interfering RNA-mediated suppression of protein kinase RNA-like endoplasmic reticulum kinase inhibited tunicamycin-induced induction of 78 kDa glucose-regulated protein, C/EBP homologous protein, pro-caspase-12 cleavage, cytosolic Ca(++) increase and apoptosis, but did not attenuate the increase in cytosolic Ca(++) level and apoptosis induced by GA. Ataxia telangiectasia mutated (ATM)-mediated c-Jun N-terminal kinase (JNK) phosphorylation and apoptosis by GA was blocked by dantrolene. The specificity of ROS-mediated ATM-JNK activation was confirmed by treatment with N-acetylcysteine, a ROS scavenger. Blockade of ATM activation by specific inhibitor KU55933, short hairpin RNA, or kinase-dead ATM overexpression suppressed JNK phosphorylation but did not completely inhibit cytosolic ROS production, mitochondrial cytochrome c release, pro-caspase-3 cleavage, and apoptosis induced by GA. Taken together, these results indicate that GA induces OC cell apoptosis by inducing the activation of mitochondrial apoptotic and ATM-JNK signal pathways, likely through ER Ca(++)-mediated ROS production.

  18. Piperine causes G1 phase cell cycle arrest and apoptosis in melanoma cells through checkpoint kinase-1 activation.

    Directory of Open Access Journals (Sweden)

    Neel M Fofaria

    Full Text Available In this study, we determined the cytotoxic effects of piperine, a major constituent of black and long pepper in melanoma cells. Piperine treatment inhibited the growth of SK MEL 28 and B16 F0 cells in a dose and time-dependent manner. The growth inhibitory effects of piperine were mediated by cell cycle arrest of both the cell lines in G1 phase. The G1 arrest by piperine correlated with the down-regulation of cyclin D1 and induction of p21. Furthermore, this growth arrest by piperine treatment was associated with DNA damage as indicated by phosphorylation of H2AX at Ser139, activation of ataxia telangiectasia and rad3-related protein (ATR and checkpoint kinase 1 (Chk1. Pretreatment with AZD 7762, a Chk1 inhibitor not only abrogated the activation of Chk1 but also piperine mediated G1 arrest. Similarly, transfection of cells with Chk1 siRNA completely protected the cells from G1 arrest induced by piperine. Piperine treatment caused down-regulation of E2F1 and phosphorylation of retinoblastoma protein (Rb. Apoptosis induced by piperine was associated with down-regulation of XIAP, Bid (full length and cleavage of Caspase-3 and PARP. Furthermore, our results showed that piperine treatment generated ROS in melanoma cells. Blocking ROS by tiron protected the cells from piperine mediated cell cycle arrest and apoptosis. These results suggest that piperine mediated ROS played a critical role in inducing DNA damage and activation of Chk1 leading to G1 cell cycle arrest and apoptosis.

  19. Altered global gene expression profiles in human gastrointestinal epithelial Caco2 cells exposed to nanosilver

    Directory of Open Access Journals (Sweden)

    Saura C. Sahu

    2016-01-01

    Full Text Available Extensive consumer exposure to food- and cosmetics-related consumer products containing nanosilver is of public safety concern. Therefore, there is a need for suitable in vitro models and sensitive predictive rapid screening methods to assess their toxicity. Toxicogenomic profile showing subtle changes in gene expressions following nanosilver exposure is a sensitive toxicological endpoint for this purpose. We evaluated the Caco2 cells and global gene expression profiles as tools for predictive rapid toxicity screening of nanosilver. We evaluated and compared the gene expression profiles of Caco-2 cells exposed to 20 nm and 50 nm nanosilver at a concentration 2.5 μg/ml. The global gene expression analysis of Caco2 cells exposed to 20 nm nanosilver showed that a total of 93 genes were altered at 4 h exposure, out of which 90 genes were up-regulated and 3 genes were down-regulated. The 24 h exposure of 20 nm silver altered 15 genes in Caco2 cells, out of which 14 were up-regulated and one was down-regulated. The most pronounced changes in gene expression were detected at 4 h. The greater size (50 nm nanosilver at 4 h exposure altered more genes by more different pathways than the smaller (20 nm one. Metallothioneins and heat shock proteins were highly up-regulated as a result of exposure to both the nanosilvers. The cellular pathways affected by the nanosilver exposure is likely to lead to increased toxicity. The results of our study presented here suggest that the toxicogenomic characterization of Caco2 cells is a valuable in vitro tool for assessing toxicity of nanomaterials such as nanosilver.

  20. Evaluation of cell types for assessment of cytogenetic damage in arsenic exposed population

    Directory of Open Access Journals (Sweden)

    Singh Keshav K

    2008-05-01

    Full Text Available Abstract Background Cytogenetic biomarkers are essential for assessing environmental exposure, and reflect adverse human health effects such as cellular damage. Arsenic is a potential clastogen and aneugen. In general, the majority of the studies on clastogenic effects of arsenic are based on frequency of micronuclei (MN study in peripheral lymphocytes, urothelial and oral epithelial cells. To find out the most suitable cell type, here, we compared cytogenetic damage through MN assay in (a various populations exposed to arsenic through drinking water retrieved from literature review, as also (b arsenic-induced Bowen's patients from our own survey. Results For literature review, we have searched the Pubmed database for English language journal articles using the following keywords: "arsenic", "micronuclei", "drinking water", and "human" in various combinations. We have selected 13 studies consistent with our inclusion criteria that measured micronuclei in either one or more of the above-mentioned three cell types, in human samples. Compared to urothelial and buccal mucosa cells, the median effect sizes measured by the difference between people with exposed and unexposed, lymphocyte based MN counts were found to be stronger. This general pattern pooled from 10 studies was consistent with our own set of three earlier studies. MN counts were also found to be stronger for lymphocytes even in arsenic-induced Bowen's patients (cases compared to control individuals having arsenic-induced non-cancerous skin lesions. Conclusion Overall, it can be concluded that MN in lymphocytes may be superior to other epithelial cells for studying arsenic-induced cytogenetic damage.

  1. Proteome Analysis of Human Follicular Thyroid Cancer Cells Exposed to the Random Positioning Machine.

    Science.gov (United States)

    Bauer, Johann; Kopp, Sascha; Schlagberger, Elisabeth Maria; Grosse, Jirka; Sahana, Jayashree; Riwaldt, Stefan; Wehland, Markus; Luetzenberg, Ronald; Infanger, Manfred; Grimm, Daniela

    2017-03-03

    Several years ago, we detected the formation of multicellular spheroids in experiments with human thyroid cancer cells cultured on the Random Positioning Machine (RPM), a ground-based model to simulate microgravity by continuously changing the orientation of samples. Since then, we have studied cellular mechanisms triggering the cells to leave a monolayer and aggregate to spheroids. Our work focused on spheroid-related changes in gene expression patterns, in protein concentrations, and in factors secreted to the culture supernatant during the period when growth is altered. We detected that factors inducing angiogenesis, the composition of integrins, the density of the cell monolayer exposed to microgravity, the enhanced production of caveolin-1, and the nuclear factor kappa B p65 could play a role during spheroid formation in thyroid cancer cells. In this study, we performed a deep proteome analysis on FTC-133 thyroid cancer cells cultured under conditions designed to encourage or discourage spheroid formation. The experiments revealed more than 5900 proteins. Their evaluation confirmed and explained the observations mentioned above. In addition, we learned that FTC-133 cells growing in monolayers or in spheroids after RPM-exposure incorporate vinculin, paxillin, focal adhesion kinase 1, and adenine diphosphate (ADP)-ribosylation factor 6 in different ways into the focal adhesion complex.

  2. The effect of K(+) on caspase activity of corneal epithelial cells exposed to UVB.

    Science.gov (United States)

    Leerar, John R; Glupker, Courtney D; Schotanus, Mark P; Ubels, John L

    2016-10-01

    Exposure of human corneal limbal epithelial (HCLE) cells to UVB triggers rapid loss of K(+) and apoptosis via activation of caspases -9, -8 and -3. It has been shown that preventing loss of intracellular K(+) can inhibit apoptosis. The goal of this study was to investigate the effect of K(+) on the UVB-induced caspase activity. HCLE cells were exposed to 150 mJ/cm(2) UVB, followed by measurement of caspase activity in cell lysates. Caspase activity was measured in the presence and absence of 100 mM K(+) in the reaction buffer. UVB-induced activity of caspases -9, -8 and -3 all decreased in the presence of 100 mM K(+). These results suggest that a role of high [K(+)] in the cell is to inhibit caspase activity. Therefore, when cells lose K(+) in response to UVB, caspases are activated and cells go into apoptosis. This supports our hypothesis that K(+) inhibits caspase activity.

  3. 44. Study the level of DNA breakage in workers exposed to styrene by single cell gel electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: Study the level of DNA breakage in workers exposed to styrene. Methods: 35 workers aging from 18 to 40 exposed to styrene half a year above were observed as exposed group, in the mean time, 57 workers in the same district who hadn't been exposed to known genotoxicant were selected as control. Bloods of them were sampled and DNA lesions were detected by single cell gel electrophoresis. Results: Compared with control, the ratio between the length of Comet tail and the total length of Comet in exposed group significantly increased, especially it raised following the styrene concentration exposed, but it was not different among different working age groups. Conclusions: DNA is damaged by styrene, and it appears as dose-response relationship.

  4. p53 modulates the AMPK inhibitor compound C induced apoptosis in human skin cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shi-Wei [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Wu, Chun-Ying [Division of Gastroenterology and Hepatology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Wang, Yen-Ting [Department of Medical Research and Education, Cheng Hsin General Hospital, Taipei, Taiwan (China); Kao, Jun-Kai [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Pediatrics, Children' s Hospital, Changhua Christian Hospital, Changhua, Taiwan (China); Lin, Chi-Chen; Chang, Chia-Che; Mu, Szu-Wei; Chen, Yu-Yu [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Chiu, Husan-Wen [Institute of Biotechnology, National Cheng-Kung University, Tainan, Taiwan (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan (China); Chang, Chuan-Hsun [Department of Surgical Oncology, Cheng Hsin General Hospital, Taipei, Taiwan (China); Department of Nutrition Therapy, Cheng Hsin General Hospital, Taipei, Taiwan (China); School of Nutrition and Health Sciences, Taipei Medical University, Taipei, Taiwan (China); Liang, Shu-Mei [Institute of Biotechnology, National Cheng-Kung University, Tainan, Taiwan (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan (China); Chen, Yi-Ju [Department of Dermatology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Huang, Jau-Ling [Department of Bioscience Technology, Chang Jung Christian University, Tainan, Taiwan (China); Shieh, Jeng-Jer, E-mail: shiehjj@vghtc.gov.tw [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan (China)

    2013-02-15

    Compound C, a well-known inhibitor of the intracellular energy sensor AMP-activated protein kinase (AMPK), has been reported to cause apoptotic cell death in myeloma, breast cancer cells and glioma cells. In this study, we have demonstrated that compound C not only induced autophagy in all tested skin cancer cell lines but also caused more apoptosis in p53 wildtype skin cancer cells than in p53-mutant skin cancer cells. Compound C can induce upregulation, phosphorylation and nuclear translocalization of the p53 protein and upregulate expression of p53 target genes in wildtype p53-expressing skin basal cell carcinoma (BCC) cells. The changes of p53 status were dependent on DNA damage which was caused by compound C induced reactive oxygen species (ROS) generation and associated with activated ataxia-telangiectasia mutated (ATM) protein. Using the wildtype p53-expressing BCC cells versus stable p53-knockdown BCC sublines, we present evidence that p53-knockdown cancer cells were much less sensitive to compound C treatment with significant G2/M cell cycle arrest and attenuated the compound C-induced apoptosis but not autophagy. The compound C induced G2/M arrest in p53-knockdown BCC cells was associated with the sustained inactive Tyr15 phosphor-Cdc2 expression. Overall, our results established that compound C-induced apoptosis in skin cancer cells was dependent on the cell's p53 status. - Highlights: ► Compound C caused more apoptosis in p53 wildtype than p53-mutant skin cancer cells. ► Compound C can upregulate p53 expression and induce p53 activation. ► Compound C induced p53 effects were dependent on ROS induced DNA damage pathway. ► p53-knockdown attenuated compound C-induced apoptosis but not autophagy. ► Compound C-induced apoptosis in skin cancer cells was dependent on p53 status.

  5. From the Cover: Exposing Imidacloprid Interferes With Neurogenesis Through Impacting on Chick Neural Tube Cell Survival.

    Science.gov (United States)

    Liu, Meng; Wang, Guang; Zhang, Shi-Yao; Zhong, Shan; Qi, Guo-Long; Wang, Chao-Jie; Chuai, Manli; Lee, Kenneth Ka Ho; Lu, Da-Xiang; Yang, Xuesong

    2016-09-01

    As a neonicotinoid pesticide, imidacloprid is widely used to control insects in agriculture and fleas on domestic animals. However, it is not known whether imidacloprid exposure negatively affects neurogenesis during embryonic development. In this study, using a chick embryo model, we investigated the effects of imidacloprid exposure on neurogenesis at the earliest stage and during late-stage embryo development. Exposing HH0 chick embryos to imidacloprid in EC culture caused neural tube defects (NTDs) and neuronal differentiation dysplasia as determined by NF/Tuj1 labeling. Furthermore, we found that F-actin accumulation on the apical side of the neural tube was suppressed by exposure to imidacloprid, and the expression of BMP4 and Shh on the dorsal and ventral sides of the neural tubes, respectively, were also reduced, which in turn affects the dorsolateral hinge points during bending of the neural plate. In addition, exposure to imidacloprid reduced cell proliferation and increased cell apoptosis, as determined by pHIS3 labeling and TUNEL staining, respectively, also contributing to the malformation. We obtained similar results in late-stage embryos exposed to imidacloprid. Finally, a bioinformatics analysis was employed to determine which genes identified in this study were involved in NTDs. The experimental evidence and bioinformatics analysis suggested that imidacloprid exposure during chick embryo development could increase the risk of NTDs and neural dysplasia.

  6. Reduced cell viability and apoptosis induction in human thyroid carcinoma and mesothelioma cells exposed to cidofovir.

    Science.gov (United States)

    Catalani, Simona; Palma, Francesco; Battistelli, Serafina; Nuvoli, Barbara; Galati, Rossella; Benedetti, Serena

    2017-02-20

    Besides its well-recognized antiviral activity, Cidofovir (CDV) has been shown to exert anticancer properties both within in vitro and in vivo models. The aim of this study was to evaluate the effects of CDV on still unexplored cultured cancer cells from human mesothelioma as well as breast, colon, liver, lung, prostate, and thyroid carcinomas. Overall, a dose- and time-dependent inhibition of cell viability was observed after CDV exposure. To clarify the mechanisms underlying CDV action, apoptotic cell death was investigated in two infected cell lines [Ist-Mes1 and Ist-Mes2 mesothelioma cells (SV40+)] and in two uninfected cell lines (NCI-H2425 mesothelioma cells and FTC-133 thyroid cancer cells), which resulted the most sensitive to CDV treatment. Reduced expression of procaspase-3 and increased expression of PARP p85 fragment were observed in both infected and uninfected mesothelioma cells, indicating apoptosis induction by CDV in a virus-independent manner. Similarly, the increase of the pro-apoptotic proteins p53, cytochrome c and caspase-3, the decrease of the survival protein Bcl-x, and the increment of Bax/Bcl-2 ratio revealed the occurrence of apoptosis in CDV-treated FTC-133. The presence of nuclear DNA fragmentation confirmed apoptotic cell death by CDV. Overall, our findings warrant further investigations to explore the therapeutic potential of CDV for human mesothelioma and follicular thyroid carcinoma.

  7. ROS-activated ATM-dependent phosphorylation of cytoplasmic substrates identified by large scale phosphoproteomics screen

    DEFF Research Database (Denmark)

    Kozlov, Sergei V; Waardenberg, Ashley J; Engholm-Keller, Kasper

    2016-01-01

    ATM (ataxia-telangiectasia, mutated) protein plays a central role in phosphorylating a network of proteins in response to DNA damage. These proteins function in signalling pathways designed to maintain the stability of the genome and minimize the risk of disease by controlling cell cycle checkpoi......ATM (ataxia-telangiectasia, mutated) protein plays a central role in phosphorylating a network of proteins in response to DNA damage. These proteins function in signalling pathways designed to maintain the stability of the genome and minimize the risk of disease by controlling cell cycle...... to identify cytoplasmic proteins altered in their phosphorylation state in control and A-T (ataxia-telangiectasia) cells in response to oxidative damage. We demonstrated that ATM was activated by oxidative damage in the cytoplasm as well as in the nucleus and identified a total of 9,833 phosphorylation sites...

  8. Gene expression profile of Jurkat cells exposed to high power terahertz radiation

    Science.gov (United States)

    Grundt, Jessica E.; Roth, Caleb C.; Rivest, Benjamin D.; Doroski, Michael L.; Payne, Jason; Ibey, Bennett L.; Wilmink, Gerald J.

    2011-03-01

    Terahertz (THz) radiation sources are now being used in a host of military, defense, and medical applications. Widespread employment of these applications has prompted concerns regarding the health effects associated with THz radiation. In this study, we examined the gene expression profile of mammalian cells exposed to THz radiation. We hypothesized that if THz radiation couples directly to cellular constituents, then exposed cells may express a specific gene expression profile indicative of ensuing damage. To test this hypothesis, Jurkat cells were irradiated with a molecular gas THz laser (2.52 THz, 636 mWcm-2, durations: 5, 10, 20, 30, 40, or 50 minutes). Viability was assessed 24 h post-exposure using MTT assays, and gene expression profiles were evaluated 4 h post-exposure using mRNA microarrays. Comparable analyses were also performed for hyperthermic positive controls (44°C for 40 minutes). We found that cellular temperatures increased by ~6 °C during THz exposures. We also found that cell death increased with exposure duration, and the median lethal dose (LD50) was calculated to be ~44 minutes. The microarray data showed that THz radiation induced the transcriptional activation of genes associated with cellular proliferation, differentiation, transcriptional activation, chaperone protein stabilization, and apoptosis. For most genes, we found that the magnitude of differential expression was comparable for both the THz and thermal exposure groups; however, several genes were specifically activated by the THz exposure. These results suggest that THz radiation may elicit effects that are not exclusively due to the temperature rise created during THz exposures (i.e. thermal effects). In future work, we plan to verify the results of our microarray experiments using qPCR techniques.

  9. Functional switching of ATM: sensor of DNA damage in proliferating cells and mediator of Akt survival signal in post-mitotic human neuron-like cells

    Institute of Scientific and Technical Information of China (English)

    Yan Li; Hua Xiong; Da-Qing Yang

    2012-01-01

    Ataxia-telangiectasia (A-T) is an autosomal recessive disorder characterized by cerebellar ataxia and oculocutaneous telangiectasias.The gene mutated in this disease,ATM (A-T,mutated),encodes a 370-kDa Ser/Thr protein kinase.ATM not only mediates cellular response to DNA damage but also acts as an activator of Akt in response to insulin.However,despite intensive studies,the mechanism underlying the neuronal degeneration symptoms of human A-T is still poorly understood.We found that the topoisomerase inhibitors etoposide and camptothecin readily induced apoptosis in undifferentiated proliferating SH-SY5Y cells but could not induce apoptosis in neuronally differentiated SH-SY5Y cells.In addition,etoposide induced p53 phosphorylation and H2AX foci formation in proliferating SH-SY5Y cells but failed to do so in differentiated SH-SY5Y cells.Moreover,while inhibition of ATM in undifferentiated SH-SY5Y cells partially protected them from etoposide-induced apoptosis,the same treatment had no effect on cell viability in differentiated SH-SY5Y cells.These results suggest that DNA damage or defective response to DNA damage is not the cause of neuronal cell death in human A-T.In contrast,we discovered that Akt phosphorylation was inhibited when ATM activity was suppressed in differentiated SH-SY5Y cells.Furthermore,inhibition of ATM induced apoptosis following serum starvation in neuronally differentiated SH-SY5Y cells but could not trigger apoptosis under the same conditions in undifferentiated proliferating SH-SY5Y cells.These results demonstrate that ATM mediates the Akt signaling and promotes cell survival in neuron-like human SH-SY5Y cells,suggesting that impaired activation of Akt is the reason for neuronal degeneration in human A-T.

  10. Genotoxic changes to rodent cells exposed in vitro to tungsten, nickel, cobalt and iron.

    Science.gov (United States)

    Bardack, Stephanie; Dalgard, Clifton L; Kalinich, John F; Kasper, Christine E

    2014-03-10

    Tungsten-based materials have been proposed as replacements for depleted uranium in armor-penetrating munitions and for lead in small-arms ammunition. A recent report demonstrated that a military-grade composition of tungsten, nickel, and cobalt induced a highly-aggressive, metastatic rhabdomyosarcoma when implanted into the leg muscle of laboratory rats to simulate a shrapnel wound. The early genetic changes occurring in response to embedded metal fragments are not known. In this study, we utilized two cultured rodent myoblast cell lines, exposed to soluble tungsten alloys and the individual metals comprising the alloys, to study the genotoxic effects. By profiling cell transcriptomes using microarray, we found slight, yet distinct and unique, gene expression changes in rat myoblast cells after 24 h metal exposure, and several genes were identified that correlate with impending adverse consequences of ongoing exposure to weapons-grade tungsten alloy. These changes were not as apparent in the mouse myoblast cell line. This indicates a potential species difference in the cellular response to tungsten alloy, a hypothesis supported by current findings with in vivo model systems. Studies examining genotoxic-associated gene expression changes in cells from longer exposure times are warranted.

  11. [An immunocytochemical study of the C-cell function of the thyroid in rats exposed on the Kosmos-2044 biosatellite].

    Science.gov (United States)

    Loginov, V I

    1993-01-01

    Immunocytochemical analysis of thyroid gland C-cells of the rats exposed to a 14-day space flight revealed a decrease in the number of C-cells, volume of their nuclei and a declined percentage of active secretory C-cells, which point to a decline of calcitonin proactive and calcitonin secretory hypofunction of the thyroid C-cells system in flown rats. Tail suspension as a microgravity model caused similar changes in C-cells.

  12. PD-L2 induction on dendritic cells exposed to Mycobacterium avium downregulates BCG-specific T cell response.

    Science.gov (United States)

    Mendoza-Coronel, Elizabeth; Camacho-Sandoval, Rosa; Bonifaz, Laura C; López-Vidal, Yolanda

    2011-01-01

    The exposure to certain species of Nontuberculous Mycobacteria (NTM) can modulate the immune response induced by Mycobacterium bovis BCG. Mycobacterium avium has been postulated as a weak inducer of dendritic cell (DC) maturation. However, how the DC exposure to M. avium could contribute to the modulation of a BCG-specific CD4+ T cell response and the molecules involved remain unknown. Here, we exposed bone marrow-derived DCs (BMDCs) to M. avium either prior to exposure to BCG or as a unique stimulus. We found that M. avium induces high expression of PD-L2 (B7-DC) in BMDCs. This was dependent on IL-10 production through the TLR2-p38 MAPK signaling pathway. Exposure to M. avium prior to BCG results in BMDCs that do not express co-stimulatory molecules and pro-inflammatory cytokines, while the expression of PD-L2 and IL-10 was maintained. BMDCs exposed to M. avium impaired the activation of BCG-specific T cells through the PD-1: PD-L interaction. This suggests that a M. avium-induced phenotype in DCs might be implicated in the induction of mechanisms of tolerance that could impact the T cell response induced by BCG vaccination.

  13. Global gene expression profiling in human lung cells exposed to cobalt

    Directory of Open Access Journals (Sweden)

    Steinmetz Gerard

    2007-06-01

    Full Text Available Abstract Background It has been estimated that more than 1 million workers in the United States are exposed to cobalt. Occupational exposure to 59 Co occurs mainly via inhalation and leads to various lung diseases. Cobalt is classified by the IARC as a possible human carcinogen (group 2B. Although there is evidence for in vivo and in vitro toxicity, the mechanisms of cobalt-induced lung toxicity are not fully known. The purpose of this work was to identify potential signatures of acute cobalt exposure using a toxicogenomic approach. Data analysis focused on some cellular processes and protein targets that are thought to be relevant for carcinogenesis, transport and biomarker research. Results A time course transcriptome analysis was performed on A549 human pulmonary cells, leading to the identification of 85 genes which are repressed or induced in response to soluble 59 Co. A group of 29 of these genes, representing the main biological functions, was assessed by quantitative RT-PCR. The expression profiles of six of them were then tested by quantitative RT-PCR in a time-dependent manner and three modulations were confirmed by Western blotting. The 85 modulated genes include potential cobalt carriers (FBXL2, ZNT1, SLC12A5, tumor suppressors or transcription factors (MAZ, DLG1, MYC, AXL and genes linked to the stress response (UBC, HSPCB, BNIP3L. We also identified nine genes coding for secreted proteins as candidates for biomarker research. Of those, TIMP2 was found to be down-regulated and this modulation was confirmed, in a dose-dependent manner, at protein level in the supernatant of exposed cells. Conclusion Most of these genes have never been described as related to cobalt stress and provide original hypotheses for further study of the effects of this metal ion on human lung epithelial cells. A putative biomarker of cobalt toxicity was identified.

  14. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accclerated carbon ions with linear energy transfers of 125.5, 200 and 700 keV/μm were measured, respectively. Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves. They are 7.86±0.17, 10.44±1.11 and 32.32±3.58 μm2 in turn. With the surviving response of V79 cells to 60Co γ-rays as a reference value, relative biological effectiveness at 10%, 20%, 50% and 80% survival levels were given for the accelerated carbon ions. The results showed that carbon ions with LET of 125.5 keV/μm had a higher value of RBE at all the four survival levels than the carbon ions with other LETs. It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200 keV/μm for carbon ions.

  15. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    LIQiang; ZHOUGuang-Ming; 等

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accelerated carbon ions with linear energy transfers of 125.5,200 and 700keV/um were measured,respectively,Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves.They are 7.86±0.17,10.44±1.11 and 32.32±3.59um2 in turn.With the surviving response of V79 cells to 60Co γ-rays as a reference value,relative biological effectiveness at 10%,20%,50%and 80% survival levels were given for the accelerated carbon ions,The results showed that carbon ions with LET of 125.5keV/um had a higher value of RBE at all the four survival levels than the carbon ions with other LETs.It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200keV/um for carbon ions.

  16. A short G1 phase imposes constitutive replication stress and fork remodelling in mouse embryonic stem cells

    DEFF Research Database (Denmark)

    Ahuja, Akshay K.; Jodkowska, Karolina; Teloni, Federico

    2016-01-01

    phosphorylation is dependent on Ataxia telangiectasia and Rad3 related (ATR) and is associated with chromatin loading of the ssDNA-binding proteins RPA and RAD51. Single-molecule analysis of replication intermediates reveals massive ssDNA gap accumulation, reduced fork speed and frequent fork reversal. All...

  17. The Bioeffects Resulting from Prokaryotic Cells and Yeast Being Exposed to an 18 GHz Electromagnetic Field.

    Science.gov (United States)

    Nguyen, The Hong Phong; Pham, Vy T H; Nguyen, Song Ha; Baulin, Vladimir; Croft, Rodney J; Phillips, Brian; Crawford, Russell J; Ivanova, Elena P

    2016-01-01

    The mechanisms by which various biological effects are triggered by exposure to an electromagnetic field are not fully understood and have been the subject of debate. Here, the effects of exposing typical representatives of the major microbial taxa to an 18 GHz microwave electromagnetic field (EMF)were studied. It appeared that the EMF exposure induced cell permeabilisation in all of the bacteria and yeast studied, while the cells remained viable (94% throughout the exposure), independent of the differences in cell membrane fatty acid and phospholipid composition. The resulting cell permeabilisation was confirmed by detection of the uptake of propidium iodine and 23 nm fluorescent silica nanospheres using transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Upon EMF exposure, the bacterial cell membranes are believed to become permeable through quasi-endocytosis processes. The dosimetry analysis revealed that the EMF threshold level required to induce the uptake of the large (46 nm) nanopsheres was between three and six EMF doses, with a specific absorption rate (SAR) of 3 kW/kg and 5 kW/kg per exposure, respectively, depending on the bacterial taxa being studied. It is suggested that the taxonomic affiliation and lipid composition (e.g. the presence of phosphatidyl-glycerol and/or pentadecanoic fatty acid) may affect the extent of uptake of the large nanospheres (46 nm). Multiple 18 GHz EMF exposures over a one-hour period induced periodic anomalous increases in the cell growth behavior of two Staphylococcus aureus strains, namely ATCC 25923 and CIP 65.8T.

  18. Large heterogeneity of mitochondrial DNA transcription and initiation of replication exposed by single-cell imaging.

    Science.gov (United States)

    Chatre, Laurent; Ricchetti, Miria

    2013-02-15

    Mitochondrial DNA (mtDNA) replication and transcription are crucial for cell function, but these processes are poorly understood at the single-cell level. We describe a novel fluorescence in situ hybridization protocol, called mTRIP (mitochondrial transcription and replication imaging protocol), that reveals simultaneously mtDNA and RNA, and that can also be coupled to immunofluorescence for in situ protein examination. mTRIP reveals mitochondrial structures engaged in initiation of DNA replication by identification of a specific sequence in the regulatory D-loop, as well as unique transcription profiles in single human cells. We observe and quantify at least three classes of mitochondrial structures: (i) replication initiation active and transcript-positive (Ia-Tp); (ii) replication initiation silent and transcript-positive (Is-Tp); and (iii) replication initiation silent and transcript-negative (Is-Tn). Thus, individual mitochondria are dramatically heterogeneous within the same cell. Moreover, mTRIP exposes a mosaic of distinct nucleic acid patterns in the D-loop, including H-strand versus L-strand transcripts, and uncoupled rRNA transcription and mtDNA initiation of replication, which might have functional consequences in the regulation of the mtDNA. Finally, mTRIP identifies altered mtDNA processing in cells with unbalanced mtDNA content and function, including in human mitochondrial disorders. Thus, mTRIP reveals qualitative and quantitative alterations that provide additional tools for elucidating the dynamics of mtDNA processing in single cells and mitochondrial dysfunction in diseases.

  19. The Bioeffects Resulting from Prokaryotic Cells and Yeast Being Exposed to an 18 GHz Electromagnetic Field.

    Directory of Open Access Journals (Sweden)

    The Hong Phong Nguyen

    Full Text Available The mechanisms by which various biological effects are triggered by exposure to an electromagnetic field are not fully understood and have been the subject of debate. Here, the effects of exposing typical representatives of the major microbial taxa to an 18 GHz microwave electromagnetic field (EMFwere studied. It appeared that the EMF exposure induced cell permeabilisation in all of the bacteria and yeast studied, while the cells remained viable (94% throughout the exposure, independent of the differences in cell membrane fatty acid and phospholipid composition. The resulting cell permeabilisation was confirmed by detection of the uptake of propidium iodine and 23 nm fluorescent silica nanospheres using transmission electron microscopy (TEM and confocal laser scanning microscopy (CLSM. Upon EMF exposure, the bacterial cell membranes are believed to become permeable through quasi-endocytosis processes. The dosimetry analysis revealed that the EMF threshold level required to induce the uptake of the large (46 nm nanopsheres was between three and six EMF doses, with a specific absorption rate (SAR of 3 kW/kg and 5 kW/kg per exposure, respectively, depending on the bacterial taxa being studied. It is suggested that the taxonomic affiliation and lipid composition (e.g. the presence of phosphatidyl-glycerol and/or pentadecanoic fatty acid may affect the extent of uptake of the large nanospheres (46 nm. Multiple 18 GHz EMF exposures over a one-hour period induced periodic anomalous increases in the cell growth behavior of two Staphylococcus aureus strains, namely ATCC 25923 and CIP 65.8T.

  20. In vitro effects of Ala16Val manganese superoxide dismutase gene polymorphism on human white blood cells exposed to methylmercury.

    Science.gov (United States)

    Algarve, T D; Barbisan, F; Ribeiro, E E; Duarte, M M M F; Mânica-Cattani, M F; Mostardeiro, C P; Lenz, A F; da Cruz, I B M

    2013-10-29

    Environmental contamination by methylmercury (MeHg) is an enormous public health problem in world regions such as Amazonia. MeHg toxic effects seem to be influenced by environmental and genetic factors. However, few studies have evaluated the genetic influences of MeHg toxicity in humans. Therefore, the aim of this study was to evaluate the genetic influence of Ala16Val manganese superoxide dismutase gene polymorphism (Ala16Val-MnSOD) on the cytotoxic effects of in vitro human leukocytes exposed to MeHg. Subjects were selected from 100 individuals aged 26.4 ± 7.3 years genotyped to Ala16Val-MnSOD polymorphism (AA = 6, VV = 6, and AV = 12) to perform in vitro testing using white blood cells (WBCs). Reactive oxygen species production was measured using 2',7'-dichlorofluorescein diacetate fluorimetric assay, and cell viability was measured using MTT assay on WBC samples from the same subjects that were both exposed and not exposed to MeHg (2.5 µM for 6 h). The results showed that AA- and VV-WBCs exposed to MeHg did not display increased reactive oxygen species levels compared to those in cells that were not exposed. However, AV-leukocytes exposed to MeHg displayed increased ROS levels. Cellular viability comparison among genotypes exposed to MeHg showed that the viability of AA-WBCs was lower than that of VV-WBC, with mean values of 3.46 ± 0.13 and 3.08 ± 0.77 (standard error), respectively (P = 0.033), whereas heterozygous cells (AV) displayed intermediate values. This difference was likely due to the higher basal H2O2 production of AA-WBCs compared to that of other genotypes. These results suggest that the Ala16Val-MnSOD polymorphism has toxicogenetic effects in human cells exposed to MeHg.

  1. Natural Products Mediated Regulation of Oxidative Stress and DNA Damage in Ultraviolet Exposed Skin Cells.

    Science.gov (United States)

    Farooqi, Ammad A; Li, Ruei-Nian; Huang, Hurng-Wern; Ismail, Muhammad; Yuan, Shyng-Shiou F; Wang, Hui-Min D; Liu, Jing-Ru; Tang, Jen-Yang; Chang, Hsueh-Wei

    2015-01-01

    Data obtained through high-throughput technologies have gradually revealed that a unique stratified epithelial architecture of human skin along with the antioxidant-response pathways provided vital defensive mechanisms against UV radiation. However, it is noteworthy that skin is a major target for toxic insult by UV radiations that can alter its structure and function. Substantial fraction of information has been added into the existing pool of knowledge related to natural products mediated biological effects in UV exposed skin cells. Accumulating evidence has started to shed light on the potential of these bioactive ingredients as protective natural products in cosmetics against UV photodamage by exerting biological effects mainly through wide ranging intracellular signalling cascades of oxidative stress and modulation of miRNAs. In this review, we have summarized recently emerging scientific evidences addressing underlying mechanisms of UV induced oxidative stress and deregulation of signalling cascades and how natural products can be used tactfully to protect against UV induced harmful effects.

  2. AT cells are not radiosensitive for simple chromosomal exchanges at low dose

    Energy Technology Data Exchange (ETDEWEB)

    Hada, Megumi; Huff, Janice L.; Patel, Zarana S. [USRA Division of Life Sciences, Houston, TX 77058 (United States); Kawata, Tetsuya [Department of Radiology, School of Medicine, Keio University, Tokyo (Japan); Pluth, Janice M. [Lawrence Berkeley National Laboratory, Life Sciences Division, One Cyclotron Road, Building 74, Berkeley, CA 94720 (United States); George, Kerry A. [Wyle, 1290 Hercules Drive, Houston, TX 77058 (United States); Cucinotta, Francis A., E-mail: Francis.A.Cucinotta@nasa.gov [NASA, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, TX 77058 (United States)

    2011-11-01

    Cells deficient in ATM (product of the gene that is mutated in ataxia telangiectasia patients) or NBS (product of the gene mutated in the Nijmegen breakage syndrome) show increased yields of both simple and complex chromosomal aberrations after high doses (>0.5 Gy) of ionizing radiation (X-rays or {gamma}-rays), however less is known on how these cells respond at low dose. Previously we had shown that the increased chromosome aberrations in ATM and NBS defective lines was due to a significantly larger quadratic dose-response term compared to normal fibroblasts for both simple and complex exchanges. The linear dose-response term for simple exchanges was significantly higher in NBS cells compared to wild type cells, but not for AT cells. However, AT cells have a high background level of exchanges compared to wild type or NBS cells that confounds the understanding of low dose responses. To understand the sensitivity differences for high to low doses, chromosomal aberration analysis was first performed at low dose-rates (0.5 Gy/d), and results provided further evidence for the lack of sensitivity for exchanges in AT cells below doses of 1 Gy. Normal lung fibroblast cells treated with KU-55933, a specific ATM kinase inhibitor, showed increased numbers of exchanges at a dose of 1 Gy and higher, but were similar to wild type cells at 0.5 Gy or below. These results were confirmed using siRNA knockdown of ATM. The present study provides evidence that the increased radiation sensitivity of AT cells for chromosomal exchanges found at high dose does not occur at low dose.

  3. Non-thermal DNA damage of cancer cells using near-infrared irradiation.

    Science.gov (United States)

    Tanaka, Yohei; Tatewaki, Naoto; Nishida, Hiroshi; Eitsuka, Takahiro; Ikekawa, Nobuo; Nakayama, Jun

    2012-08-01

    Previously, we reported that near-infrared irradiation that simulates solar near-infrared irradiation with pre- and parallel-irradiational cooling can non-thermally induce cytocidal effects in cancer cells. To explore these effects, we assessed cell viability, DNA damage response pathways, and the percentage of mitotic cancer cells after near-infrared treatment. Further, we evaluated the anti-cancer effects of near-infrared irradiation compared with doxorubicin in xenografts in nude mice by measuring tumor volume and assessing protein phosphorylation by immunoblot analysis. The cell viability of A549 lung adenocarcinoma cells was significantly decreased after three rounds of near-infrared irradiation at 20 J/cm(2). Apoptotic cells were observed in near-infrared treated cells. Moreover, near-infrared treatment increased the phosphorylation of ataxia-telangiectasia mutated (ATM) at Ser(1981), H2AX at Ser(139), Chk1 at Ser(317), structural maintenance of chromosome (SMC) 1 at Ser(966), and p53 at Ser(15) in A549 cells compared with control. Notably, near-infrared treatment induced the formation of nucleic foci of γH2AX. The percentage of mitotic A549 cells, as measured by histone H3 phosphorylation, decreased significantly after three rounds of near-infrared irradiation at 20 J/cm(2). Both near-infrared and doxorubicin inhibited the tumor growth of MDA-MB435 melanoma cell xenografts in nude mice and increased the phosphorylation of p53 at Ser(15), Chk1 at Ser(317), SMC1 at Ser(966), and H2AX at Ser(139) compared with control mice. These results indicate that near-infrared irradiation can non-thermally induce cytocidal effects in cancer cells as a result of activation of the DNA damage response pathway. The near-infrared irradiation schedule used here reduces discomfort and side effects. Therefore, this strategy may have potential application in the treatment of cancer.

  4. Noise Removal with Maintained Spatial Resolution in Raman Images of Cells Exposed to Submicron Polystyrene Particles

    Directory of Open Access Journals (Sweden)

    Linnea Ahlinder

    2016-04-01

    Full Text Available The biodistribution of 300 nm polystyrene particles in A549 lung epithelial cells has been studied with confocal Raman spectroscopy. This is a label-free method in which particles and cells can be imaged without using dyes or fluorescent labels. The main drawback with Raman imaging is the comparatively low spatial resolution, which is aggravated in heterogeneous systems such as biological samples, which in addition often require long measurement times because of their weak Raman signal. Long measurement times may however induce laser-induced damage. In this study we use a super-resolution algorithm with Tikhonov regularization, intended to improve the image quality without demanding an increased number of collected pixels. Images of cells exposed to polystyrene particles have been acquired with two different step lengths, i.e., the distance between pixels, and compared to each other and to corresponding images treated with the super-resolution algorithm. It is shown that the resolution after application of super-resolution algorithms is not significantly improved compared to the theoretical limit for optical microscopy. However, to reduce noise and artefacts in the hyperspectral Raman images while maintaining the spatial resolution, we show that it is advantageous to use short mapping step lengths and super-resolution algorithms with appropriate regularization. The proposed methodology should be generally applicable for Raman imaging of biological samples and other photo-sensitive samples.

  5. Ethanol Metabolism Activates Cell Cycle Checkpoint Kinase, Chk2

    Science.gov (United States)

    Clemens, Dahn L.; Mahan Schneider, Katrina J.; Nuss, Robert F.

    2011-01-01

    Chronic ethanol abuse results in hepatocyte injury and impairs hepatocyte replication. We have previously shown that ethanol metabolism results in cell cycle arrest at the G2/M transition, which is partially mediated by inhibitory phosphorylation of the cyclin-dependent kinase, Cdc2. To further delineate the mechanisms by which ethanol metabolism mediates this G2/M arrest, we investigated the involvement of upstream regulators of Cdc2 activity. Cdc2 is activated by the phosphatase Cdc25C. The activity of Cdc25C can, in turn, be regulated by the checkpoint kinase, Chk2, which is regulated by the kinase ataxia telangiectasia mutated (ATM). To investigate the involvement of these regulators of Cdc2 activity, VA-13 cells, which are Hep G2 cells modified to efficiently express alcohol dehydrogenase, were cultured in the presence or absence of 25 mM ethanol. Immunoblots were performed to determine the effects of ethanol metabolism on the activation of Cdc25C, Chk2, and ATM. Ethanol metabolism increased the active forms of ATM, and Chk2, as well as the phosphorylated form of Cdc25C. Additionally, inhibition of ATM resulted in approximately 50% of the cells being rescued from the G2/M cell cycle arrest, and ameliorated the inhibitory phosphorylation of Cdc2. Our findings demonstrate that ethanol metabolism activates ATM. ATM can activate the checkpoint kinase Chk2, resulting in phosphorylation of Cdc25C, and ultimately in the accumulation of inactive Cdc2. This may, in part, explain the ethanol metabolism-mediated impairment in hepatocyte replication, which may be important in the initiation and progression of alcoholic liver injury. PMID:21924579

  6. Anti-inflammatory activity of the basolateral fraction of Caco-2 cells exposed to a rosemary supercritical extract

    NARCIS (Netherlands)

    Arranz, E.; Mes, J.J.; Wichers, H.J.; Jaime, L.; Reglero, G.; Santoyo, S.

    2015-01-01

    The anti-inflammatory activity of the basolateral fraction of Caco-2 cells exposed to a rosemary supercritical extract was examined. Uptake of rosemary extract fractions was tested on Caco-2 cell monolayers (2–12 h incubation times) and the quantification of carnosic acid and carnosol was performed

  7. The Roles of 4β-Hydroxywithanolide E from Physalis peruviana on the Nrf2-Anti-Oxidant System and the Cell Cycle in Breast Cancer Cells.

    Science.gov (United States)

    Peng, Chieh Yu; You, Bang Jau; Lee, Chia Lin; Wu, Yang Chang; Lin, Wen Hsin; Lu, Te Ling; Chang, Fei-Ching; Lee, Hong Zin

    2016-01-01

    4[Formula: see text]-Hydroxywithanolide E is an active component of the extract of Physalis peruviana that has been reported to exhibit antitumor effects. Although the involvement of reactive oxygen species (ROS) production and the ataxia-telangiectasia mutated protein (ATM)-dependent DNA damage signaling pathway in 4[Formula: see text]-hydroxywithanolide E-induced apoptosis of breast cancer MCF-7 cells was demonstrated in our previous study, the relationship between ROS production and the cellular defense system response in 4[Formula: see text]-hydroxywithanolide E-induced cell death requires further verification. The present study suggests that ROS play an important role in 4[Formula: see text]-hydroxywithanolide E-induced MCF-7 cell death in which anti-oxidants, such as glutathione or N-acetylcysteine, can resist the 4[Formula: see text]-hydroxywithanolide E-induced accumulation of ROS and cell death. Furthermore, N-acetylcysteine or glutathione can reverse the 4[Formula: see text]-hydroxywithanolide E-induced changes in the cell cycle distribution and the expression of cell cycle regulators. We found that the 4[Formula: see text]-hydroxywithanolide E-induced ROS accumulation was correlated with the upregulation of Nrf2 and Nrf2-downstream genes, such as antioxidative defense enzymes. In general, the activity of Nrf2 is regulated by the Ras signalling pathway. However, we demonstrated that Nrf2 was activated during 4[Formula: see text]-hydroxywithanolide E-induced MCF-7 cell death in spite of the 4[Formula: see text]-hydroxywithanolide E-induced inhibition of the Ras/Raf/ERK pathway. The activity and protein expression of superoxide dismutase and catalase were involved in the 4[Formula: see text]-hydroxywithanolide E-induced ROS production in MCF-7 cells. Furthermore, 4[Formula: see text]-hydroxywithanolide E was demonstrated to significantly reduce the sizes of the tumor nodules in the human breast cancer MDA-MB231 xenograft tumor model.

  8. Interphase Death of Chinese Hamster Ovary Cells Exposed to Accelerated Heavy Ions

    Directory of Open Access Journals (Sweden)

    P. Mehnati

    2007-06-01

    Full Text Available Introduction: Heavy ions are nucleus of elements of iron, argon, carbon and neon that all carry positive electrical charges. For these particles to be useful in radiotherapy they need to accelerated to high energy by more than thousand mega volts. Also the cosmic environment is considered to be a complicated mixture of highly energetic photons and heavy ions such as iron. Therefore, the health risks to astronauts during long mission should be considered.  Materials and Methods: The induction of interphase death was tested on Chinese hamster ovary cells by exposing them to accelerated heavy ions (carbon, neon, argon and iron of 10-2000 linear energy transfers (LETs. The fraction of cells that underwent interphase death was determined by observing individual cells with time-lapse photography (direct method as well as by the indirect method of counting cells undergoing interphase death made visible by the addition of caffeine (indirect method. Results: The interphase death due to the exposure to X- rays is increased linearly as the dose exceeds the threshold dose of 10 Gy. Whereas the interphase death increases at a higher rate due to the exposure to high LET heavy ions and no threshold dose was observed. The range of LET values corresponding to the maximum RBE for the interphase death is 120-230 keV/µm. The probability of inducing the interphase death by a single heavy ion traversing through the nucleus is about 0.04-0.08. Discussion and Conclusion: The relative biological effectiveness (RBE of heavy ions as compared to X- rays as determined at the 50% level of induction is increased with LET. It reached a maximum value at a LET of approximately 230 keV/µm and then decreased with further increase in LET. The range of LET values corresponding to the maximum RBE appears to be narrower for interphase death than for reproductive death.

  9. Cytogenomics of hexavalent chromium (Cr6+ exposed cells: A comprehensive review

    Directory of Open Access Journals (Sweden)

    Akanksha Nigam

    2014-01-01

    Full Text Available The altered cellular gene expression profile is being hypothesized as the possible molecular basis navigating the onset or progress of various morbidities. This hypothesis has been evaluated here in respect of Cr 6+ induced toxicity. Several studies using gene microarray show selective and strategic dysregulations of cellular genes and pathways induced by Cr 6+ . Relevant literature has been reviewed to unravel these changes in different test systems after exposure to Cr 6+ and also to elucidate association if any, of the altered cytogenomics with Cr 6+ induced toxicity or carcinogenicity. The aim was to verify the hypothesis for critical role of altered cytogenomics in onset of Cr 6+ induced biological / clinical effects by identifying genes modulated commonly by the toxicant irrespective of test system or test concentrations / doses, and by scrutinizing their importance in regulation of the flow of mechanistically linked events crucial for resultant morbidities. Their probability as biomarkers to monitor the toxicant induced biological changes is speculative. The modulated genes have been found to cluster under the pathways that manage onset of oxidative stress, DNA damage, apoptosis, cell-cycle regulation, cytoskeleton, morphological changes, energy metabolism, biosynthesis, oncogenes, bioenergetics, and immune system critical for toxicity. In these studies, the identity of genes has been found to differ remarkably; albeit the trend of pathways′ dysregulation has been found to remain similar. We conclude that the intensity of dysregulation of genes or pathways involved in mechanistic events forms a sub-threshold or threshold level depending upon the dose and type (including speciation of the toxicant, duration of exposure, type of target cells, and niche microenvironment of cells, and the intensity of sub-threshold or threshold level of the altered cytogenomics paves way in toxicant exposed cells eventually either to opt for reversal to

  10. Genetic polymorphisms and surface expression of CTLA-4 and PD-1 on T cells of silica-exposed workers.

    Science.gov (United States)

    Rocha, Michelle C; Santos, Leonilda M B; Bagatin, Ericson; Cohen Tervaert, Jan W; Damoiseaux, Jan G M C; Lido, Alessandro V; Longhini, Ana L; Torello, Cristiane O; Queiroz, Mary L S

    2012-11-01

    Exposure to silica dust has been examined as a possible risk factor for autoimmune diseases, including scleroderma, rheumatoid arthritis and systemic lupus erythematosus. Since CTLA-4 [CD152] and PD-1 [CD279] are important for the maintenance of peripheral tolerance by regulating T cell responsiveness, we evaluated the expression of these molecules on the surface of CD4 and CD8 T cells, as well as single nucleotide polymorphisms (SNP) in CTLA-4 and PDCD1 genes, of 70 silica-exposed workers and 30 non-exposed, age-, ethnically- and sex-matched controls. Expression of CTLA-4 was significantly (P<0.05) reduced in CD4 T cells of exposed individuals [median=0.1% and interquartile range, IQR 0.0-0.1% (exposed), median=0.20%, IQR 0.0-0.4% (control)]. Also the expression of PD-1 was significantly (P<0.0001) reduced in both CD4 [median=0.9%, IQR 0.4-2.3% (exposed), median=5.7%, IQR 1.4-13.3% (control)] and CD8 T cells [median=0.9%, IQR 0.3-1.9% (exposed), median=5.0%, IQR 3.4-8.9% (control)]. The study of polymorphisms demonstrated a lower frequency of the A allele in the analysis of the PD1.3 SNP in the exposed group, which might be associated with the lower expression of PD-1 on the surface of CD4 T cells. Our findings provide evidence for the association of silica exposure and the maintenance of self-tolerance, i.e., the susceptibility to autoimmune disorders.

  11. Novel leukocyte agonists are released by endothelial cells exposed to peroxide.

    Science.gov (United States)

    Patel, K D; Zimmerman, G A; Prescott, S M; McIntyre, T M

    1992-07-25

    Reactive oxygen species do not activate isolated neutrophils, yet in vivo, such oxidants promote their adhesion to, and subsequent migration through, the vascular wall. We show human endothelial cells exposed to t-butylhydroperoxide shed large, sealed membrane vesicles that contained potent neutrophil agonists. This activity migrated on TLC like platelet-activating factor (PAF). Since neutrophils have a receptor for this phospholipid, which recognizes its unique characteristics including the short sn-2 acetyl residue, we examined the effect of PAF receptor antagonists and PAF acetylhydrolase on this activity. Structurally unrelated PAF receptor antagonists blocked neutrophil stimulation by vesicular phospholipids, and digestion with PAF acetylhydrolase, which is specific for short sn-2 residues, destroyed this activity. However, metabolic labeling, inhibition of synthesis, phospholipase A1 digestion, and high performance liquid chromatographic studies demonstrated that the vesicles did not contain PAF. Instead, the bioactivity migrated on high performance liquid chromatography like the phospholipids generated by oxidative fragmentation of synthetic arachidonoyl phosphatidylcholine that we have shown previously (Smiley, P. L., Stremler, K. E., Prescott, S. M., Zimmerman, G. A., and McIntyre, T. M. (1991) J. Biol. Chem. 266, 11104-11110) to stimulate neutrophils through their receptor for PAF. Thus, peroxide treatment of endothelial cells fragments cellular phosphatidylcholines, forming novel PAF-like phospholipids, and induces the shedding of membrane vesicles that contain these bioactive phospholipids.

  12. Aspartate Rescues S-phase Arrest Caused by Suppression of Glutamine Utilization in KRas-driven Cancer Cells.

    Science.gov (United States)

    Patel, Deven; Menon, Deepak; Bernfeld, Elyssa; Mroz, Victoria; Kalan, Sampada; Loayza, Diego; Foster, David A

    2016-04-22

    During G1-phase of the cell cycle, normal cells respond first to growth factors that indicate that it is appropriate to divide and then later in G1 to the presence of nutrients that indicate sufficient raw material to generate two daughter cells. Dividing cells rely on the "conditionally essential" amino acid glutamine (Q) as an anaplerotic carbon source for TCA cycle intermediates and as a nitrogen source for nucleotide biosynthesis. We previously reported that while non-transformed cells arrest in the latter portion of G1 upon Q deprivation, mutant KRas-driven cancer cells bypass the G1 checkpoint, and instead, arrest in S-phase. In this study, we report that the arrest of KRas-driven cancer cells in S-phase upon Q deprivation is due to the lack of deoxynucleotides needed for DNA synthesis. The lack of deoxynucleotides causes replicative stress leading to activation of the ataxia telangiectasia and Rad3-related protein (ATR)-mediated DNA damage pathway, which arrests cells in S-phase. The key metabolite generated from Q utilization was aspartate, which is generated from a transaminase reaction whereby Q-derived glutamate is converted to α-ketoglutarate with the concomitant conversion of oxaloacetate to aspartate. Aspartate is a critical metabolite for both purine and pyrimidine nucleotide biosynthesis. This study identifies the molecular basis for the S-phase arrest caused by Q deprivation in KRas-driven cancer cells that arrest in S-phase in response to Q deprivation. Given that arresting cells in S-phase sensitizes cells to apoptotic insult, this study suggests novel therapeutic approaches to KRas-driven cancers.

  13. Acute lymphoblastic leukemia in children with associated genetic conditions other than Down's syndrome. The AIEOP experience.

    Science.gov (United States)

    Ziino, Ottavio; Rondelli, Roberto; Micalizzi, Concetta; Luciani, Matteo; Conter, Valentino; Aricò, Maurizio

    2006-01-01

    We retrospectively reviewed the databases of seven studies on acute lymphoblastic leukemia (ALL) by the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) to identify patients with associated genetic disease, other than Down's syndrome. Forty-two patients were reported to have associated genetic conditions that included beta-thalassemia (n=10), ataxia-telangiectasia (n=5), neurofibromatosis (n=3), Sotos syndrome (n=2) and other individual conditions. Patients with ataxia-telangiectasia, all with T-cell ALL, had a higher frequency of adverse events.

  14. Attenuation of the DNA Damage Response by Transforming Growth Factor-Beta Inhibitors Enhances Radiation Sensitivity of Non–Small-Cell Lung Cancer Cells In Vitro and In Vivo

    Energy Technology Data Exchange (ETDEWEB)

    Du, Shisuo; Bouquet, Sophie; Lo, Chen-Hao; Pellicciotta, Ilenia; Bolourchi, Shiva [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States); Parry, Renate [Varian Medical Systems, Palo Alto, California (United States); Barcellos-Hoff, Mary Helen, E-mail: mhbarcellos-hoff@nyumc.org [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States)

    2015-01-01

    Purpose: To determine whether transforming growth factor (TGF)-β inhibition increases the response to radiation therapy in human and mouse non–small-cell lung carcinoma (NSCLC) cells in vitro and in vivo. Methods and Materials: TGF-β–mediated growth response and pathway activation were examined in human NSCLC NCI-H1299, NCI-H292, and A549 cell lines and murine Lewis lung cancer (LLC) cells. Cells were treated in vitro with LY364947, a small-molecule inhibitor of the TGF-β type 1 receptor kinase, or with the pan-isoform TGF-β neutralizing monoclonal antibody 1D11 before radiation exposure. The DNA damage response was assessed by ataxia telangiectasia mutated (ATM) or Trp53 protein phosphorylation, γH2AX foci formation, or comet assay in irradiated cells. Radiation sensitivity was determined by clonogenic assay. Mice bearing syngeneic subcutaneous LLC tumors were treated with 5 fractions of 6 Gy and/or neutralizing or control antibody. Results: The NCI-H1299, A549, and LLC NSCLC cell lines pretreated with LY364947 before radiation exposure exhibited compromised DNA damage response, indicated by decreased ATM and p53 phosphorylation, reduced γH2AX foci, and increased radiosensitivity. The NCI-H292 cells were unresponsive. Transforming growth factor-β signaling inhibition in irradiated LLC cells resulted in unresolved DNA damage. Subcutaneous LLC tumors in mice treated with TGF-β neutralizing antibody exhibited fewer γH2AX foci after irradiation and significantly greater tumor growth delay in combination with fractionated radiation. Conclusions: Inhibition of TGF-β before radiation attenuated DNA damage recognition and increased radiosensitivity in most NSCLC cells in vitro and promoted radiation-induced tumor control in vivo. These data support the rationale for concurrent TGF-β inhibition and RT to provide therapeutic benefit in NSCLC.

  15. Distribution of Chromosome Breakpoints in Human Epithelial Cells Exposed to Low- and High-LET Radiations

    Science.gov (United States)

    Hada, Megumi; Cucinotta, Francis; Wu, Honglu

    2009-01-01

    The advantage of the multicolor banding in situ hybridization (mBAND) technique is not only its ability to identify simultaneously both inter- and intrachromosome exchanges, but also the ability to measure the breakpoint location along the length of the chromosome in a precision that is unmatched with other traditional banding techniques. Breakpoints on specific regions of a chromosome have been known to associate with specific cancers. The breakpoint distribution in cells after low- and high-LET radiation exposures will also provide the data for biophysical modeling of the chromatin structure, as well as the data for the modeling the formation of radiation-induced chromosome aberrations. In a series of experiments, we studied low- and high-LET radiation-induced chromosome aberrations using the mBAND technique with chromosome 3 painted in 23 different colored bands. Human epithelial cells (CH1 84B5F5/M10) were exposed in vitro to Cs- 137 rays at both low and high dose rates, secondary neutrons with a broad energy spectrum at a low dose rate and 600 MeV/u Fe ions at a high dose rate. The data of both inter- and intrachromosome aberrations involving the painted chromosome have been reported previously. Here we present data of the location of the chromosome breaks along the length of chromosome 3 in the cells after exposures to each of the four radiation scenarios. In comparison to the expected breakpoint distribution based on the length of the bands, the observed distribution appeared to be non-random for both the low- and high-LET radiations. In particular, hot spots towards both ends of the chromosome were found after low-LET irradiations of either low or high dose rates. For both high-LET radiation types (Fe ions and neutrons), the breakpoint distributions were similar, and were much smoother than that for low-LET radiation. The dependence of the breakpoint distribution on the radiation quality requires further investigations.

  16. Proteomic responses of human intestinal Caco-2 cells exposed to silver nanoparticles and ionic silver.

    Science.gov (United States)

    Oberemm, Axel; Hansen, Ulf; Böhmert, Linda; Meckert, Christine; Braeuning, Albert; Thünemann, Andreas F; Lampen, Alfonso

    2016-03-01

    Even although quite a number of studies have been performed so far to demonstrate nanoparticle-specific effects of substances in living systems, clear evidence of these effects is still under debate. The present study was designed as a comparative proteomic analysis of human intestinal cells exposed to a commercial silver nanoparticle reference material and ions from AgNO3. A two-dimensional gel electrophoresis/MALDI mass spectrometry (MS)-based proteomic analysis was conducted after 24-h incubation of differentiated Caco-2 cells with non-cytotoxic and low cytotoxic silver concentrations (2.5 and 25 µg ml(-1) nanosilver, 0.5 and 5 µg ml(-1) AgNO3). Out of an overall number of 316 protein spots differentially expressed at a fold change of ≥ 1.4 or ≤ -1.4 in all treatments, 169 proteins could be identified. In total, 231 spots were specifically deregulated in particle-treated groups compared with 41 spots, which were limited to AgNO3-treatments. Forty-four spots (14 %) were commonly deregulated by both types of treatment. A considerable fraction of the proteins differentially expressed after treatment with nanoparticles is related to protein folding, synthesis or modification of proteins as well as cellular assembly and organization. Overlays of networks obtained for particulate and ionic treatments showed matches, indicating common mechanisms of combined particle and ionic silver exposure and exclusive ionic silver treatment. However, proteomic responses of Caco-2 cells treated with higher concentrations of silver species also showed some differences, for example regarding proteins related to fatty acid and energy metabolism, suggesting an induction of also some different molecular mechanisms for particle exposure and ionic treatment.

  17. Comet assay in gill cells of Prochilodus lineatus exposed in vivo to cypermethrin.

    Science.gov (United States)

    Poletta, G L; Gigena, F; Loteste, A; Parma, M J; Kleinsorge, E C; Simoniello, M F

    2013-11-01

    Agricultural chemicals can induce genetic alterations on aquatic organisms that have been associated with effects on growth, reproduction and population dynamics. The evaluation of DNA damage in fish using the comet assay (CA) frequently involves the utilization of erythrocytes. However, epithelial gill cells (EGC) can be more sensitive, as they are constantly dividing and in direct contact with potentially stressing compounds from the aquatic environment. The aim of the present study was to evaluate (1) the sensitivity and suitability of epithelial gill cells of Prochilodus lineatus in response to different genotoxic agents through the application of the CA, (2) the induction of DNA damage in this cell population after in vivo exposure to cypermethrin. Baseline value of the CA damage index (DI) for EGC of juvenile P. lineatus was 144.68±5.69. Damage increased in a dose-dependent manner after in vitro exposure of EGC to methyl methanesulfonate (MMS) and H2O2, two known genotoxic agents. In vivo exposure of fish to cypermethrin induced a significant increase in DNA DI of EGC at 0.150μg/l (DI: 239.62±6.21) and 0.300μg/l (270.63±2.09) compared to control (150.25±4.38) but no effect was observed at 0.075μg/l (168.50±10.77). This study shows that EGC of this species are sensitive for the application of the CA, demonstrating DNA damage in response to alkylation (MMS), oxidative damage (H2O2), and to the insecticide cypermethryn. These data, together with our previous study on DNA damage induction on erythrocytes of this species, provides useful information for future work involving biomonitoring in regions where P. lineatus is naturally exposed to pesticides and other genotoxic agents.

  18. Proliferation assay of mouse embryonic stem (ES) cells exposed to atmospheric-pressure plasmas at room temperature

    Science.gov (United States)

    Miura, Taichi; Ando, Ayumi; Hirano, Kazumi; Ogura, Chika; Kanazawa, Tatsuya; Ikeguchi, Masamichi; Seki, Atsushi; Nishihara, Shoko; Hamaguchi, Satoshi

    2014-11-01

    Proliferation assays of mouse embryonic stem (ES) cells have been performed with cell culture media exposed to atmospheric-pressure plasmas (APPs), which generate reactive species in the media at room temperature. It is found that serum in cell culture media functions as a scavenger of highly reactive species and tends to protect cells in the media against cellular damage. On the other hand, if serum is not present in a cell culture medium when it is exposed to APP, the medium becomes cytotoxic and cannot be detoxified by serum added afterwards. Plasma-induced cytotoxic media hinder proliferation of mouse ES cells and may even cause cell death. It is also shown by nuclear magnetic resonance spectroscopy that organic compounds in cell culture media are in general not significantly modified by plasma exposure. These results indicate that if there is no serum in media when they are exposed to APPs, highly reactive species (such as OH radicals) generated in the media by the APP exposure are immediately converted to less reactive species (such as H2O2), which can no longer readily react with serum that is added to the medium after plasma exposure. This study has clearly shown that it is these less reactive species, rather than highly reactive species, that make the medium cytotoxic to mouse ES cells.

  19. Anti-tumor activity of the ATR inhibitor AZD6738 in HER2 positive breast cancer cells.

    Science.gov (United States)

    Kim, Hee-Jun; Min, Ahrum; Im, Seock-Ah; Jang, Hyemin; Lee, Kyung Hun; Lau, Alan; Lee, Miso; Kim, Seongyeong; Yang, Yaewon; Kim, Jungeun; Kim, Tae Yong; Oh, Do-Youn; Brown, Jeffrey; O'Connor, Mark J; Bang, Yung-Jue

    2017-01-01

    Ataxia telangiectasia and Rad3-related (ATR) proteins are sensors of DNA damage, which induces homologous recombination (HR)-dependent repair. ATR is a master regulator of DNA damage repair (DDR), signaling to control DNA replication, DNA repair and apoptosis. Therefore, the ATR pathway might be an attractive target for developing new drugs. This study was designed to investigate the antitumor effects of the ATR inhibitor, AZD6738 and its underlying mechanism in human breast cancer cells. Growth inhibitory effects of AZD6738 against human breast cancer cell lines were studied using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (methyl thiazolyl tetrazolium, MTT) assay. Cell cycle analysis, Western blotting, immunofluorescence and comet assays were also performed to elucidate underlying mechanisms of AZD6738 action. Anti-proliferative and DDR inhibitory effects of AZD6738 were demonstrated in human breast cancer cell lines. Among 13 cell lines, the IC50 values of nine cell lines were less than 1 μmol/L using MTT assay. Two cell lines, SK-BR-3 and BT-474, were chosen for further evaluation focused on human epidermal growth factor receptor 2 (HER2)-positive breast cancer cells. Sensitive SK-BR-3 but not the less sensitive BT-474 breast cancer cells showed increased level of apoptosis and S phase arrest and reduced expression levels of phosphorylated check-point kinase 1 (CHK1) and other repair markers. Decreased functional CHK1 expression induced DNA damage accumulation due to HR inactivation. AZD6738 showed synergistic activity with cisplatin. Understanding the antitumor activity and mechanisms of AZD6738 in HER2-positive breast cancer cells creates the possibility for future clinical trials targeting DDR in HER2-positive breast cancer treatment.

  20. Simultaneous inhibition of ATR and PARP sensitizes colon cancer cell lines to irinotecan

    Directory of Open Access Journals (Sweden)

    Atlal eAbu-Sanad

    2015-07-01

    Full Text Available Enhanced DNA damage repair is one mechanism involved in colon cancer drug resistance. Thus, targeting molecular components of repair pathways with specific small molecule inhibitors may improve the efficacy of chemotherapy. ABT-888 and VE-821, inhibitors of poly-ADP-ribose-polymerase (PARP and the serine/threonine-kinase Ataxia telangiectasia related (ATR, respectively, were used to treat colon cancer cell lines in combination with the topoisomerase-I inhibitor irinotecan (SN38. Our findings show that each of these DNA repair inhibitors utilized alone at nontoxic single agent concentrations resulted in sensitization to SN38 producing a 1.4 to 3 fold reduction in the 50% inhibitory concentration (IC50 of SN38 in three colon cancer cell lines. When combined together, nontoxic concentrations of ABT-888 and VE-821 produced a 4.5 to 27 fold reduction in the IC50 of SN38 with the HCT-116 colon cancer cells demonstrating the highest sensitization as compared to LoVo and HT-29 colon cancer cells. Furthermore, the combination of all three agents was associated with maximal G2-M arrest and enhanced DNA-damage (γH2AX in all three colon cancer cell lines. The mechanism of this enhanced sensitization was associated with: (a maximal suppression of SN38 induced PARP activity in the presence of both inhibitors and (b ABT-888 producing partial abrogation of the VE-821 enhancement of SN38 induced DNA-PK phosphorylation, resulting in more unrepaired DNA damage; these alterations were only present in the HCT-116 cells which have reduced levels of ATM. This novel combination of DNA repair inhibitors may be useful to enhance the activity of DNA damaging chemotherapies such as irinotecan and help produce sensitization to this drug in colon cancer.

  1. Growth Inhibition Occurs Independently of Cell Mortality in Tomato (Solanum lycopersicum) Exposed to High Cadmium Concentrations

    Institute of Scientific and Technical Information of China (English)

    Christine Delpérée; Stanley Lutts

    2008-01-01

    In order to analyze the adaptation potential of tomato shoots to a sudden increase in Cd concentration, tomato plants (Solanum lycopersicum L. var. Ailsa Craig) were exposed under controlled environmental conditions to a high dose of this heavy metal (250 μM CdCl2>) in nutrient solution for 7 and 14 d. Both root and shoot growth was completely inhibited but all plants remained alive until the end of the treatment. Cell viability remained unaffected but the activity of the mitochondrial alternative pathway was stimulated by Cd stress at the expense of the cytochrome pathway. Cadmium concentration was higher in roots than in shoots and a decrease In the rate of net Cd translocation was noticed during the second week of stress. Cadmium decreased both leaf conductance (g1>) and chlorophyll concentration. However, the effect on net CO2 assimilation remained limited and soluble sugars accumulated in leaves. Photochemical efficiency of PSll (FvlFm) was not affected despite a decrease in the number of reaction centers and an inhibition of electron transfer to acceptors of PSII. It is concluded that tomato shoot may sustain short term exposure to high doses of cadmium despite growth inhibition. This property implies several physiological strategies linked to both avoidance and tolerance mechanisms.

  2. Disrupted NOS signaling in lymphatic endothelial cells exposed to chronically increased pulmonary lymph flow.

    Science.gov (United States)

    Datar, Sanjeev A; Gong, Wenhui; He, Youping; Johengen, Michael; Kameny, Rebecca J; Raff, Gary W; Maltepe, Emin; Oishi, Peter E; Fineman, Jeffrey R

    2016-07-01

    Associated abnormalities of the lymphatic circulation are well described in congenital heart disease. However, their mechanisms remain poorly elucidated. Using a clinically relevant ovine model of a congenital cardiac defect with chronically increased pulmonary blood flow (shunt), we previously demonstrated that exposure to chronically elevated pulmonary lymph flow is associated with: 1) decreased bioavailable nitric oxide (NO) in pulmonary lymph; and 2) attenuated endothelium-dependent relaxation of thoracic duct rings, suggesting disrupted lymphatic endothelial NO signaling in shunt lambs. To further elucidate the mechanisms responsible for this altered NO signaling, primary lymphatic endothelial cells (LECs) were isolated from the efferent lymphatic of the caudal mediastinal node in 4-wk-old control and shunt lambs. We found that shunt LECs (n = 3) had decreased bioavailable NO and decreased endothelial nitric oxide synthase (eNOS) mRNA and protein expression compared with control LECs (n = 3). eNOS activity was also low in shunt LECs, but, interestingly, inducible nitric oxide synthase (iNOS) expression and activity were increased in shunt LECs, as were total cellular nitration, including eNOS-specific nitration, and accumulation of reactive oxygen species (ROS). Pharmacological inhibition of iNOS reduced ROS in shunt LECs to levels measured in control LECs. These data support the conclusion that NOS signaling is disrupted in the lymphatic endothelium of lambs exposed to chronically increased pulmonary blood and lymph flow and may contribute to decreased pulmonary lymphatic bioavailable NO.

  3. Knockout of Ccr2 alleviates photoreceptor cell death in rodent retina exposed to chronic blue light.

    Science.gov (United States)

    Hu, Zizhong; Zhang, Yi; Wang, Junling; Mao, Pingan; Lv, Xuehua; Yuan, Songtao; Huang, Zhengru; Ding, Yuzhi; Xie, Ping; Liu, Qinghuai

    2016-11-10

    Age-related macular degeneration (AMD), the leading cause of visual loss after the age of 60 years, is a degenerative retinal disease involving a variety of environmental and hereditary factors. Although it has been implicated that immune system is involved in the disease progression, the exact role that microglia has is still unclear. Here we demonstrated that knockout of Ccr2 gene could alleviate photoreceptor cell death in mice retinas exposed to chronic blue light. In Ccr2(-/-) mice, a damaged microglia recruitment was shown in retina and this could protect the visual function in electroretinogram and alleviate the photoreceptor apoptosis, which thus helped attenuate the blue light-induced retinopathy. We further found an increased co-location of NLRP3, Iba-1, and IL-1β in fluorescence and a concomitant increased protein expression of NLRP3, caspase-1, and IL-1β in western blotting in chronic blue light-induced retinopathy. Moreover, the activation of microglia and their cellular NLRP3 inflammasomes occurred as an earlier step before the structural and functional damage of the mice retinas, which collectively supported that microglial NLRP3 inflammasome might be the key to the chronic blue light-induced retinopathy.

  4. Persistent oxidative stress in human neural stem cells exposed to low fluences of charged particles.

    Science.gov (United States)

    Baulch, Janet E; Craver, Brianna M; Tran, Katherine K; Yu, Liping; Chmielewski, Nicole; Allen, Barrett D; Limoli, Charles L

    2015-08-01

    Exposure to the space radiation environment poses risks for a range of deleterious health effects due to the unique types of radiation encountered. Galactic cosmic rays are comprised of a spectrum of highly energetic nuclei that deposit densely ionizing tracks of damage along the particle trajectory. These tracks are distinct from those generated by the more sparsely ionizing terrestrial radiations, and define the geometric distribution of the complex cellular damage that results when charged particles traverse the tissues of the body. The exquisite radiosensitivity of multipotent neural stem and progenitor cells found within the neurogenic regions of the brain predispose the central nervous system to elevated risks for radiation induced sequelae. Here we show that human neural stem cells (hNSC) exposed to different charged particles at space relevant fluences exhibit significant and persistent oxidative stress. Radiation induced oxidative stress was found to be most dependent on total dose rather than on the linear energy transfer of the incident particle. The use of redox sensitive fluorogenic dyes possessing relative specificity for hydroxyl radicals, peroxynitrite, nitric oxide (NO) and mitochondrial superoxide confirmed that most irradiation paradigms elevated reactive oxygen and nitrogen species (ROS and RNS, respectively) in hNSC over a 1 week interval following exposure. Nitric oxide synthase (NOS) was not the major source of elevated nitric oxides, as the use of NOS inhibitors had little effect on NO dependent fluorescence. Our data provide extensive evidence for the capability of low doses of charged particles to elicit marked changes in the metabolic profile of irradiated hNSC. Radiation induced changes in redox state may render the brain more susceptible to the development of neurocognitive deficits that could affect an astronaut's ability to perform complex tasks during extended missions in deep space.

  5. Persistent oxidative stress in human neural stem cells exposed to low fluences of charged particles

    Directory of Open Access Journals (Sweden)

    Janet E. Baulch

    2015-08-01

    Full Text Available Exposure to the space radiation environment poses risks for a range of deleterious health effects due to the unique types of radiation encountered. Galactic cosmic rays are comprised of a spectrum of highly energetic nuclei that deposit densely ionizing tracks of damage along the particle trajectory. These tracks are distinct from those generated by the more sparsely ionizing terrestrial radiations, and define the geometric distribution of the complex cellular damage that results when charged particles traverse the tissues of the body. The exquisite radiosensitivity of multipotent neural stem and progenitor cells found within the neurogenic regions of the brain predispose the central nervous system to elevated risks for radiation induced sequelae. Here we show that human neural stem cells (hNSC exposed to different charged particles at space relevant fluences exhibit significant and persistent oxidative stress. Radiation induced oxidative stress was found to be most dependent on total dose rather than on the linear energy transfer of the incident particle. The use of redox sensitive fluorogenic dyes possessing relative specificity for hydroxyl radicals, peroxynitrite, nitric oxide (NO and mitochondrial superoxide confirmed that most irradiation paradigms elevated reactive oxygen and nitrogen species (ROS and RNS, respectively in hNSC over a 1 week interval following exposure. Nitric oxide synthase (NOS was not the major source of elevated nitric oxides, as the use of NOS inhibitors had little effect on NO dependent fluorescence. Our data provide extensive evidence for the capability of low doses of charged particles to elicit marked changes in the metabolic profile of irradiated hNSC. Radiation induced changes in redox state may render the brain more susceptible to the development of neurocognitive deficits that could affect an astronaut’s ability to perform complex tasks during extended missions in deep space.

  6. Speciation of arsenic in Euglena gracilis cells exposed to As(V).

    Science.gov (United States)

    Miot, Jennyfer; Morin, Guillaume; Skouri-Panet, Fériel; Férard, Céline; Poitevin, Antonine; Aubry, Emmanuel; Ona-Nguema, Georges; Juillot, Farid; Guyot, François; Brown, Gordon E

    2009-05-01

    Euglena gracilis is a photosynthetic eukaryote ubiquitous in arsenic-polluted acid mine drainages and is locally exposed to As(III) and As(V) concentrations up to 250 and 100 mg L(-1), respectively. Here, arsenic speciation in E. graciliswas determined by X-ray absorption spectroscopy and selected (bio)chemical methods on cells grown at nonlimiting phosphate concentrations. Our results suggest the following detoxification scheme: (1) uptake of As(V) from solution in competition with phosphate, (2) intracellular reduction to As(III), (3) complexation by cytoplasmic proteic thiol ligands of low molecular weight, and (4) As(III) export from the cell. However, at As(V) concentrations >100 mg L(-1), growth rate is markedly lowered and As(V) remains mostly unreduced during the extended lag period. Intracellular As(V) is found to be exclusively concentrated in the membrane + nucleus fraction, suggesting that arsenate could substitute for phosphate groups in membranes or in phosphate-containing macromolecules. Thus, arsenic species are partitioned, with As(III)-thiol compounds concentrated in the cytoplasmic proteic pool and As(V)-compounds associated with the membrane + nucleus fraction. The increasing growth delay observed with increasing initial As(V) concentration in the culture medium is proposed to result from the combination of a higher As(V) uptake and limiting intracellular As(V) reduction rate and As(III) export rate. Under high As(V) exposure conditions (200 mg L(-1)) the reduction step is found to be the most limiting step for detoxification.

  7. ATM-deficient human fibroblast cells are resistant to low levels of DNA double-strand break induced apoptosis and subsequently undergo drug-induced premature senescence

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun; Jo, Yong Hwa; Cho, Chang Hoon; Choe, Wonchae; Kang, Insug; Baik, Hyung Hwan [Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, 26 Kyunghee-daero, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Yoon, Kyung-Sik, E-mail: sky9999@khu.ac.kr [Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, 26 Kyunghee-daero, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer A-T cells were not hypersensitive to low levels of DNA DSBs. Black-Right-Pointing-Pointer A-T cells have enhanced Akt but defect in activation of p53 and apoptotic proteins. Black-Right-Pointing-Pointer A-T cells underwent premature senescence after DNA damage accumulated. Black-Right-Pointing-Pointer Chemotherapeutic effect in cancer therapy may be associated with premature senescence. -- Abstract: DNA DSBs are induced by IR or radiomimetic drugs such as doxorubicin. It has been indicated that cells from ataxia-telangiectasia patients are highly sensitive to radiation due to defects in DNA repair, but whether they have impairment in apoptosis has not been fully elucidated. A-T cells showed increased sensitivity to high levels of DNA damage, however, they were more resistant to low doses. Normal cells treated with combination of KU55933, a specific ATM kinase inhibitor, and doxorubicin showed increased resistance as they do in a similar manner to A-T cells. A-T cells have higher viability but more DNA breaks, in addition, the activations of p53 and apoptotic proteins (Bax and caspase-3) were deficient, but Akt expression was enhanced. A-T cells subsequently underwent premature senescence after treatment with a low dose of doxorubicin, which was confirmed by G2 accumulation, senescent morphology, and SA-{beta}-gal positive until 15 days repair incubation. Finally, A-T cells are radio-resistant at low doses due to its defectiveness in detecting DNA damage and apoptosis, but the accumulation of DNA damage leads cells to premature senescence.

  8. B cells play key roles in th2-type airway immune responses in mice exposed to natural airborne allergens.

    Science.gov (United States)

    Drake, Li Yin; Iijima, Koji; Hara, Kenichiro; Kobayashi, Takao; Kephart, Gail M; Kita, Hirohito

    2015-01-01

    Humans are frequently exposed to various airborne allergens. In addition to producing antibodies, B cells participate in immune responses via various mechanisms. The roles of B cells in allergic airway inflammation and asthma have been controversial. We examined the functional importance of B cells in a mouse model of asthma, in which mice were exposed repeatedly to common airborne allergens. Naïve wild-type BALB/c mice or B cell-deficient JH-/- mice were exposed intranasally to a cocktail of allergen extracts, including Alternaria, Aspergillus, and house dust mite, every other day for two weeks. Ovalbumin was included in the cocktail to monitor the T cell immune response. Airway inflammation, lung pathology, and airway reactivity were analyzed. The airway exposure of naïve wild type mice to airborne allergens induced robust eosinophilic airway inflammation, increased the levels of Th2 cytokines and chemokines in the lung, and increased the reactivity to inhaled methacholine. These pathological changes and immune responses were attenuated in B cell-deficient JH-/- mice. The allergen-induced expansion of CD4+ T cells was impaired in the lungs and draining lymph nodes of JH-/- mice. Furthermore, lymphocytes from JH-/- mice failed to produce Th2 cytokines in response to ovalbumin re-stimulation in vitro. Our results suggest that B cells are required for the optimal development of Th2-type immune responses and airway inflammation when exposed to common airborne allergens. The therapeutic targeting of B cells may be beneficial to treat asthma in certain patients.

  9. B cells play key roles in th2-type airway immune responses in mice exposed to natural airborne allergens.

    Directory of Open Access Journals (Sweden)

    Li Yin Drake

    Full Text Available Humans are frequently exposed to various airborne allergens. In addition to producing antibodies, B cells participate in immune responses via various mechanisms. The roles of B cells in allergic airway inflammation and asthma have been controversial. We examined the functional importance of B cells in a mouse model of asthma, in which mice were exposed repeatedly to common airborne allergens. Naïve wild-type BALB/c mice or B cell-deficient JH-/- mice were exposed intranasally to a cocktail of allergen extracts, including Alternaria, Aspergillus, and house dust mite, every other day for two weeks. Ovalbumin was included in the cocktail to monitor the T cell immune response. Airway inflammation, lung pathology, and airway reactivity were analyzed. The airway exposure of naïve wild type mice to airborne allergens induced robust eosinophilic airway inflammation, increased the levels of Th2 cytokines and chemokines in the lung, and increased the reactivity to inhaled methacholine. These pathological changes and immune responses were attenuated in B cell-deficient JH-/- mice. The allergen-induced expansion of CD4+ T cells was impaired in the lungs and draining lymph nodes of JH-/- mice. Furthermore, lymphocytes from JH-/- mice failed to produce Th2 cytokines in response to ovalbumin re-stimulation in vitro. Our results suggest that B cells are required for the optimal development of Th2-type immune responses and airway inflammation when exposed to common airborne allergens. The therapeutic targeting of B cells may be beneficial to treat asthma in certain patients.

  10. Nuclear PTEN controls DNA repair and sensitivity to genotoxic stress

    Science.gov (United States)

    Bassi, C; Ho, J; Srikumar, T; Dowling, RJO; Gorrini, C; Miller, SJ; Mak, TW; Neel, BG; Raught, B; Stambolic, V

    2016-01-01

    Loss of function of the Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) tumor suppressor gene is associated with many human cancers. In the cytoplasm, PTEN antagonizes the Phosphatidylinositol 3′ kinase (PI3K) signaling pathway. PTEN also accumulates in the nucleus, where its function remains poorly understood. We demonstrate that SUMOylation (SUMO) of PTEN controls its nuclear localization. In cells exposed to genotoxic stress, SUMO-PTEN was rapidly excluded from the nucleus dependent on the protein kinase Ataxia telangiectasia mutated (ATM). Cells lacking nuclear PTEN were hypersensitive to DNA damage, while PTEN-deficient cells were susceptible to killing by a combination of genotoxic stress and a small molecule PI3K inhibitor both in vitro and in vivo. Our findings may have implications for individualized therapy for patients with PTEN-deficient tumors. PMID:23888040

  11. DNA double-strand breaks activate ATM independent of mitochondrial dysfunction in A549 cells.

    Science.gov (United States)

    Kalifa, Lidza; Gewandter, Jennifer S; Staversky, Rhonda J; Sia, Elaine A; Brookes, Paul S; O'Reilly, Michael A

    2014-10-01

    Excessive nuclear or mitochondrial DNA damage can lead to mitochondrial dysfunction, decreased energy production, and increased generation of reactive oxygen species (ROS). Although numerous cell signaling pathways are activated when cells are injured, the ataxia telangiectasia mutant (ATM) protein has emerged as a major regulator of the response to both mitochondrial dysfunction and nuclear DNA double-strand breaks (DSBs). Because mitochondrial dysfunction is often a response to excessive DNA damage, it has been difficult to determine whether nuclear and/or mitochondrial DNA DSBs activate ATM independent of mitochondrial dysfunction. In this study, mitochondrial and nuclear DNA DSBs were generated in the A549 human lung adenocarcinoma cell line by infecting with retroviruses expressing the restriction endonuclease PstI fused to a mitochondrial targeting sequence (MTS) or nuclear localization sequence (NLS) and a hemagglutinin antigen epitope tag (HA). Expression of MTS-PstI-HA or NLS-PstI-HA activated the DNA damage response defined by phosphorylation of ATM, the tumor suppressor protein p53 (TP53), KRAB-associated protein (KAP)-1, and structural maintenance of chromosomes (SMC)-1. Phosphorylated ATM and SMC1 were detected in nuclear fractions, whereas phosphorylated TP53 and KAP1 were detected in both mitochondrial and nuclear fractions. PstI also enhanced expression of the cyclin-dependent kinase inhibitor p21 and inhibited cell growth. This response to DNA damage occurred in the absence of detectable mitochondrial dysfunction and excess production of ROS. These findings reveal that DNA DSBs are sufficient to activate ATM independent of mitochondrial dysfunction and suggest that the activated form of ATM and some of its substrates are restricted to the nuclear compartment, regardless of the site of DNA damage.

  12. Identification of genes differentially expressed between benign and osteopontin transformed rat mammary epithelial cells

    Directory of Open Access Journals (Sweden)

    Rudland Philip S

    2009-02-01

    Full Text Available Abstract Background Osteopontin is a secreted, integrin-binding and phosphorylated acidic glycoprotein which has an important role in tumor progression. Findings In this study, we have utilized suppressive subtractive hybridization (SSH to evaluate OPN regulated gene expression, using the Rama 37 benign non-invasive rat mammary cell line and a subclone, Rama 37-OPN. Rama 37-OPN was produced by stably transfecting Rama 37 with an OPN expression vector and it demonstrates increased malignant properties in vitro. Sequence and expression array analysis of the respective cDNA libraries of over 1600 subtracted cDNA fragments revealed 982 ESTs, 45 novel sequences and 659 known genes. The known up-regulated genes in the Rama 37-OPN library code for proteins with a variety of functions including those involved in metabolism, cell adhesion and migration, signal transduction and in apoptosis. Four of the most differentially expressed genes between the benign and in vitro malignant rat mammary cell lines are tumor protein translationally controlled I (TPTI, aryl hydrocarbon receptor nuclear translocator (ARNT, ataxia telangiectasia mutated (ATM and RAN GTPase (RAN. The largest difference (ca 10,000 fold between the less aggressively (MCF-7, ZR-75 and more aggressively malignant (MDA MB 231, MDA MB 435S human breast cancer cell lines is that due to RAN, the next is that due to osteopontin itself. Conclusion The results suggest that enhanced properties associated with the malignant state in vitro induced by osteopontin may be due to, in part, overexpression of RAN GTPase and these biological results are the subject of a subsequent publication 1.

  13. Human parvovirus B19 DNA replication induces a DNA damage response that is dispensable for cell cycle arrest at phase G2/M.

    Science.gov (United States)

    Lou, Sai; Luo, Yong; Cheng, Fang; Huang, Qinfeng; Shen, Weiran; Kleiboeker, Steve; Tisdale, John F; Liu, Zhengwen; Qiu, Jianming

    2012-10-01

    Human parvovirus B19 (B19V) infection is highly restricted to human erythroid progenitor cells, in which it induces a DNA damage response (DDR). The DDR signaling is mainly mediated by the ATR (ataxia telangiectasia-mutated and Rad3-related) pathway, which promotes replication of the viral genome; however, the exact mechanisms employed by B19V to take advantage of the DDR for virus replication remain unclear. In this study, we focused on the initiators of the DDR and the role of the DDR in cell cycle arrest during B19V infection. We examined the role of individual viral proteins, which were delivered by lentiviruses, in triggering a DDR in ex vivo-expanded primary human erythroid progenitor cells and the role of DNA replication of the B19V double-stranded DNA (dsDNA) genome in a human megakaryoblastoid cell line, UT7/Epo-S1 (S1). All the cells were cultured under hypoxic conditions. The results showed that none of the viral proteins induced phosphorylation of H2AX or replication protein A32 (RPA32), both hallmarks of a DDR. However, replication of the B19V dsDNA genome was capable of inducing the DDR. Moreover, the DDR per se did not arrest the cell cycle at the G(2)/M phase in cells with replicating B19V dsDNA genomes. Instead, the B19V nonstructural 1 (NS1) protein was the key factor in disrupting the cell cycle via a putative transactivation domain operating through a p53-independent pathway. Taken together, the results suggest that the replication of the B19V genome is largely responsible for triggering a DDR, which does not perturb cell cycle progression at G(2)/M significantly, during B19V infection.

  14. PTEN enhances G2/M arrest in etoposide-treated MCF‑7 cells through activation of the ATM pathway.

    Science.gov (United States)

    Zhang, Ruopeng; Zhu, Li; Zhang, Lirong; Xu, Anli; Li, Zhengwei; Xu, Yijuan; He, Pei; Wu, Maoqing; Wei, Fengxiang; Wang, Chenhong

    2016-05-01

    As an effective tumor suppressor, phosphatase and tensin homolog (PTEN) has attracted the increased attention of scientists. Recent studies have shown that PTEN plays unique roles in the DNA damage response (DDR) and can interact with the Chk1 pathway. However, little is known about how PTEN contributes to DDR through the ATM-Chk2 pathway. It is well-known that etoposide induces G2/M arrest in a variety of cell lines, including MCF-7 cells. The DNA damage-induced G2/M arrest results from the activation of protein kinase ataxia telangiectasia mutated (ATM), followed by the activation of Chk2 that subsequently inactivates CDC25C, resulting in G2/M arrest. In the present study, we assessed the contribution of PTEN to the etoposide-induced G2/M cell cycle arrest. PTEN was knocked down in MCF-7 cells by specific shRNA, and the effects of PTEN on the ATM-Chk2 pathway were investigated through various approaches. The results showed that knockdown of PTEN strongly antagonized ATM activation in response to etoposide treatment, and thereby reduced the phosphorylation level of ATM substrates, including H2AX, P53 and Chk2. Furthermore, depletion of PTEN reduced the etoposide-induced phosphorylation of CDC25C and strikingly compromised etoposide-induced G2/M arrest in the MCF-7 cells. Altogether, we demonstrated that PTEN plays a unique role in etoposide-induced G2/M arrest by facilitating the activation of the ATM pathway, and PTEN was required for the proper activation of checkpoints in response to DNA damage in MCF-7 cells.

  15. BIGEL analysis of gene expression in HL60 cells exposed to X rays or 60 Hz magnetic fields

    Science.gov (United States)

    Balcer-Kubiczek, E. K.; Zhang, X. F.; Han, L. H.; Harrison, G. H.; Davis, C. C.; Zhou, X. J.; Ioffe, V.; McCready, W. A.; Abraham, J. M.; Meltzer, S. J.

    1998-01-01

    We screened a panel of 1,920 randomly selected cDNAs to discover genes that are differentially expressed in HL60 cells exposed to 60 Hz magnetic fields (2 mT) or X rays (5 Gy) compared to unexposed cells. Identification of these clones was accomplished using our two-gel cDNA library screening method (BIGEL). Eighteen cDNAs differentially expressed in X-irradiated compared to control HL60 cells were recovered from a panel of 1,920 clones. Differential expression in experimental compared to control cells was confirmed independently by Northern blotting of paired total RNA samples hybridized to each of the 18 clone-specific cDNA probes. DNA sequencing revealed that 15 of the 18 cDNA clones produced matches with the database for genes related to cell growth, protein synthesis, energy metabolism, oxidative stress or apoptosis (including MYC, neuroleukin, copper zinc-dependent superoxide dismutase, TC4 RAS-like protein, peptide elongation factor 1alpha, BNIP3, GATA3, NF45, cytochrome c oxidase II and triosephosphate isomerase mRNAs). In contrast, BIGEL analysis of the same 1,920 cDNAs revealed no differences greater than 1.5-fold in expression levels in magnetic-field compared to sham-exposed cells. Magnetic-field-exposed and control samples were analyzed further for the presence of mRNA encoding X-ray-responsive genes by hybridization of the 18 specific cDNA probes to RNA from exposed and control HL60 cells. Our results suggest that differential gene expression is induced in approximately 1% of a random pool of cDNAs by ionizing radiation but not by 60 Hz magnetic fields under the present experimental conditions.

  16. Differential effects in cells exposed to ultra-short, high intensity electric fields: cell survival, DNA damage, and cell cycle analysis.

    Science.gov (United States)

    Stacey, M; Stickley, J; Fox, P; Statler, V; Schoenbach, K; Beebe, S J; Buescher, S

    2003-12-09

    High power, nanosecond pulsed electric field (nsPEF) effects have been focused on bacterial decontamination, but the impact on mammalian cells is now being revealed. During nsPEF applications, electrical pulses of 10, 60 or 300 ns durations were applied to cells using electric field amplitudes as high as 300 kV/cm. Because of the ultra-short pulse durations, the energy transferred to cells is negligible, and only non-thermal effects are observed. We investigated the genotoxicity of nsPEF on adherent and non-adherent cell lines including 10 human lines and one mouse cell line with different origin and growth characteristics. We present data examining the effects of nsPEF exposure on cell survival assessed by clonogenic formation or live cell count; DNA damage determined by the comet assay and chromosome aberrations; and cell cycle parameters by measuring the mitotic indices of exposed cells. Using each of these indicators, we observed differential effects among cell types with non-adherent cells being more sensitive to the genotoxic effects of nsPEF exposures than adherent cells. Non-adherent cultures showed a rapid decrease in cell viability (90%), induction of DNA damage, and a decrease in the number of cells reaching mitosis after one 60 ns pulse with an electric field intensity of 60 kV/cm. These effects were not observed in cells grown as adherent cultures, with the exception of the mouse 3T3 cell line, which showed survival characteristics similar to non-adherent cultures. These data suggest that nsPEF genotoxicity may be cell type specific, and therefore have potential applications in the selective removal of one cell type from another, for example, in diseased states.

  17. Unirradiated cells rescue cells exposed to ionizing radiation: Activation of NF-κB pathway in irradiated cells

    Energy Technology Data Exchange (ETDEWEB)

    Lam, R.K.K. [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); Han, Wei [Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Yu, K.N., E-mail: peter.yu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong (Hong Kong)

    2015-12-15

    Highlights: • Rescue effect was observed in both irradiated and HeLa and NIH/3T3 cells. • Novel setup and procedures to separate the rescue signals and the bystander signals. • Confirmed activation of NF-κB pathway in rescue effect using activation inhibitor. • Confirmed activation of NF-κB pathway in rescue effect using anti-NF-κB p65 antibody. - Abstract: We studied the involvement of NF-κB pathway activation in the rescue effect in HeLa and NIH/3T3 cells irradiated by α particles. Firstly, upon irradiation by 5 cGy of α particles, for both cell lines, the numbers of 53BP1 foci/cell at 12 h post-irradiation were significantly smaller when only 2.5% of the cell population was irradiated as compared to 100% irradiation, which demonstrated the rescue effect. Secondly, we studied the effect of NF-κB on the rescue effect through the use of the NF-κB activation inhibitor BAY-11-7082. Novel experimental setup and procedures were designed to prepare the medium (CM) which had conditioned the bystander cells previously partnered with irradiated cells, to ensure physical separation between rescue and bystander signals. BAY-11-7082 itself did not inflict DNA damages in the cells or have effects on activation of the NF-κB response pathway in the irradiated cells through direct irradiation. The rescue effect was induced in both cell lines by the CM, which was abrogated if BAY-11-7082 was added to the CM. Thirdly, we studied the effect of NF-κB on the rescue effect through staining for phosphorylated NF-κB (p-NF-κB) expression using the anti-NF-κB p65 (phospho S536) antibody. When the fraction of irradiated cells dropped from 100% to 2.5%, the p-NF-κB expression in the cell nuclei of irradiated NIH/3T3 cells increased significantly, while that in the cell nuclei of irradiated HeLa cells also increased although not significantly. Moreover, the p-NF-κB expression in the cell nuclei of irradiated HeLa cells and NIH/3T3 cells treated with CM also increased

  18. Increase in DNA damage in lymphocytes and micronucleus frequency in buccal cells in silica-exposed workers

    Directory of Open Access Journals (Sweden)

    Ajanta Halder

    2012-01-01

    Full Text Available The alkaline single cell gel electrophoresis (comet assay was applied to study the genotoxic properties of silica in human peripheral blood lymphocytes (PBL. The study was designed to evaluate the DNA damage of lymphocytes and the end points like micronuclei from buccal smears in a group of 45 workers, occupationally exposed to silica, from small mines and stone quarries. The results were compared to 20 sex and age matched normal individuals. There was a statistically significant difference in the damage levels between the exposed group and the control groups. The types of damages (type I -type 1V were used to measure the DNA damage. The numbers of micronuclei were higher in the silica-exposed population. The present study suggests that the silica exposure can induce lymphocyte DNA damage and produces significant variation of micronuclei in buccal smear.

  19. Teratogen-induced apoptotic cell death: does the apoptotic machinery act as a protector of embryos exposed to teratogens?

    Science.gov (United States)

    Torchinsky, Arkady; Fein, Amos; Toder, Vladimir

    2005-12-01

    Considerable evidence has been collected demonstrating that many teratogens induce apoptotic cell death in embryonic structures that turn out to be malformed in fetuses and newborns. Apoptosis is a genetically regulated process that is realized by the activation of death and pro-survival signaling cascades, and the interplay between these cascades determines whether the cell exposed to apoptotic stimuli dies or survives. Therefore, there is intense interest in understanding how the apoptotic machinery functions in embryos exposed to teratogens. However, the interpretation of the results obtained remains problematic. The main problem is that excessive embryonic cell death, regardless of its nature, if uncompensated for, ultimately leads to maldevelopment or embryonic death. Therefore, we can easily interpret results when the intensity of teratogen-induced cell death and the severity or incidence of teratogen-induced anomalies directly correlate with each other. However, when teratogen-induced cell death is not followed by the formation of anomalies, a usual explanation is that teratogen-induced apoptotic cell death contributes to the renewal of teratogen-targeted cell populations by promoting the removal of injured cells. It is clear that such an explanation leaves vague the role of the anti-apoptotic signaling mechanism (and, hence, the apoptotic machinery as a whole) with respect to protecting the embryo against teratogenic stress. In this review, we summarize the data from studies addressing the function of the apoptotic machinery in embryos exposed to teratogens, and then we discuss approaches to interpreting the results of these studies. We hypothesize that activation of a proapoptotic signaling in teratogen-targeted cell populations is a necessary condition for an anti-apoptotic signaling that counteracts the process of maldevelopment to be activated. If such a scenario is true, we need to modify our approaches to choosing molecular targets for studies

  20. Impact of lysosomal storage disorders on biology of mesenchymal stem cells: Evidences from in vitro silencing of glucocerebrosidase (GBA) and alpha-galactosidase A (GLA) enzymes.

    Science.gov (United States)

    Squillaro, Tiziana; Antonucci, Ivana; Alessio, Nicola; Esposito, Anna; Cipollaro, Marilena; Melone, Mariarosa Anna Beatrice; Peluso, Gianfranco; Stuppia, Liborio; Galderisi, Umberto

    2017-01-18

    Lysosomal storage disorders (LDS) comprise a group of rare multisystemic diseases resulting from inherited gene mutations that impair lysosomal homeostasis. The most common LSDs, Gaucher disease (GD), and Fabry disease (FD) are caused by deficiencies in the lysosomal glucocerebrosidase (GBA) and alpha-galactosidase A (GLA) enzymes, respectively. Given the systemic nature of enzyme deficiency, we hypothesized that the stem cell compartment of GD and FD patients might be also affected. Among stem cells, mesenchymal stem cells (MSCs) are a commonly investigated population given their role in hematopoiesis and the homeostatic maintenance of many organs and tissues. Since the impairment of MSC functions could pose profound consequences on body physiology, we evaluated whether GBA and GLA silencing could affect the biology of MSCs isolated from bone marrow and amniotic fluid. Those cell populations were chosen given the former's key role in organ physiology and the latter's intriguing potential as an alternative stem cell model for human genetic disease. Our results revealed that GBA and GLA deficiencies prompted cell cycle arrest along with the impairment of autophagic flux and an increase of apoptotic and senescent cell percentages. Moreover, an increase in ataxia-telangiectasia-mutated staining 1 hr after oxidative stress induction and a return to basal level at 48 hr, along with persistent gamma-H2AX staining, indicated that MSCs properly activated DNA repair signaling, though some damages remained unrepaired. Our data therefore suggest that MSCs with reduced GBA or GLA activity are prone to apoptosis and senescence due to impaired autophagy and DNA repair capacity.

  1. ATM Expression Predicts Veliparib and Irinotecan Sensitivity in Gastric Cancer by Mediating P53-Independent Regulation of Cell Cycle and Apoptosis.

    Science.gov (United States)

    Subhash, Vinod Vijay; Tan, Shi Hui; Yeo, Mei Shi; Yan, Fui Leng; Peethala, Praveen C; Liem, Natalia; Krishnan, Vaidehi; Yong, Wei Peng

    2016-12-01

    Identification of synthetically lethal cellular targets and synergistic drug combinations is important in cancer chemotherapy as they help to overcome treatment resistance and increase efficacy. The Ataxia Telangiectasia Mutated (ATM) kinase is a nuclear protein that plays a major role in the initiation of DNA repair signaling and cell-cycle check points during DNA damage. Although ATM was shown to be associated with poor prognosis in gastric cancer, its implications as a predictive biomarker for cancer chemotherapy remain unexplored. The present study evaluated ATM-induced synthetic lethality and its role in sensitization of gastric cancer cells to PARP and TOP1 inhibitors, veliparib (ABT-888) and irinotecan (CPT-11), respectively. ATM expression was detected in a panel of gastric cell lines, and the IC50 against each inhibitors was determined. The combinatorial effect of ABT-888 and CPT-11 in gastric cancer cells was also determined both in vitro and in vivo ATM deficiency was found to be associated with enhanced sensitivity to ABT-888 and CPT-11 monotherapy, hence suggesting a mechanism of synthetic lethality. Cells with high ATM expression showed reduced sensitivity to monotherapy; however, they showed a higher therapeutic effect with ABT-888 and CPT-11 combinatorial therapy. Furthermore, ATM expression was shown to play a major role in cellular homeostasis by regulating cell-cycle progression and apoptosis in a P53-independent manner. The present study highlights the clinical utility of ATM expression as a predictive marker for sensitivity of gastric cancer cells to PARP and TOP1 inhibition and provides a deeper mechanistic insight into ATM-dependent regulation of cellular processes. Mol Cancer Ther; 15(12); 3087-96. ©2016 AACR.

  2. Micronuclei in peripheral blood and bone marrow cells of mice exposed to 42 GHz electromagnetic millimeter waves.

    Science.gov (United States)

    Vijayalaxmi; Logani, Mahendra K; Bhanushali, Ashok; Ziskin, Marvin C; Prihoda, Thomas J

    2004-03-01

    The genotoxic potential of 42.2 +/- 0.2 GHz electromagnetic millimeter-wave radiation was investigated in adult male BALB/c mice. The radiation was applied to the nasal region of the mice for 30 min/day for 3 consecutive days. The incident power density used was 31.5 +/- 5.0 mW/cm2. The peak specific absorption rate was calculated as 622 +/- 100 W/kg. Groups of mice that were injected with cyclophosphamide (15 mg/kg body weight), a drug used in the treatment of human malignancies, were also included to determine if millimeter-wave radiation exposure had any influence on drug-induced genotoxicity. Concurrent sham-exposed and untreated mice were used as controls. The extent of genotoxicity was assessed from the incidence of micronuclei in polychromatic erythrocytes of peripheral blood and bone marrow cells collected 24 h after treatment. The results indicated that the incidence of micronuclei in 2000 polychromatic erythrocytes was not significantly different among untreated, millimeter wave-exposed, and sham-exposed mice. The group mean incidences were 6.0 +/- 1.6, 5.1 +/- 1.5 and 5.1 +/- 1.3 in peripheral blood and 9.1 +/- 1.1, 9.3 +/- 1.6 and 9.1 +/- 1.6 in bone marrow cells, respectively. Mice that were injected with cyclophosphamide exhibited significantly increased numbers of micronuclei, 14.6 +/- 2.7 in peripheral blood and 21.3 +/- 3.9 in bone marrow cells (Pwave-exposed and sham-exposed mice; the mean incidences were 14.3 +/- 2.8 and 15.4 +/- 3.0 in peripheral blood and 23.5 +/- 2.3 and 22.1 +/- 2.5 in bone marrow cells, respectively. Thus there was no evidence for the induction of genotoxicity in the peripheral blood and bone marrow cells of mice exposed to electromagnetic millimeter-wave radiation. Also, millimeter-wave radiation exposure did not influence cyclophosphamide-induced micronuclei in either type of cells.

  3. CtIP-dependent DNA resection is required for DNA damage checkpoint maintenance but not initiation

    DEFF Research Database (Denmark)

    Kousholt, Arne Nedergaard; Fugger, Kasper; Hoffmann, Saskia

    2012-01-01

    To prevent accumulation of mutations, cells respond to DNA lesions by blocking cell cycle progression and initiating DNA repair. Homology-directed repair of DNA breaks requires CtIP-dependent resection of the DNA ends, which is thought to play a key role in activation of ATR (ataxia telangiectasia...

  4. Individual radiosensitivity does not correlate with radiation-induced apoptosis in lymphoblastoid cell lines or CD{sup 3+} lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Wistop, A.; Keller, U.; Grabenbauer, G.G.; Sauer, R.; Distel, L.V.R. [Dept. of Radiation Oncology, Friedrich Alexander Univ. Erlangen-Nuremberg, Erlangen (Germany); Sprung, C.N. [Div. of Research, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia)

    2005-05-01

    Background and purpose: spontaneous and radiation-induced apoptosis of lymphoblastoid cell lines (LCLs) derived from healthy donors, cancer patients and donors with radiosensitivity syndromes as well as CD{sup 3+} lymphocytes from patients with {>=} grade 3 late toxicity were investigated as a possible marker for the detection of individual radiosensitivity. These investigations are based on the hypothesis that hypersensitive patients have reduced levels of apoptosis after in vitro irradiation as a result of a defect in the signaling pathway. Material and methods: Epstein-Barr virus-(EBV-)transformed LCLs derived from five healthy donors, seven patients with heterozygous or homozygous genotype for ataxia-telangiectasia or Nijmegen breakage syndrome and five patients with {>=} grade 3 late toxicity (RTOG) were investigated. In addition, CD{sup 3+} lymphocytes from 21 healthy individuals and 18 cancer patients including five patients with a proven cellular hypersensitivity to radiation were analyzed. Cells were irradiated in vitro with a dose of 2 and 5 Gy and were incubated for 48 h. Apoptotic rates were measured by the TUNEL assay followed by customized image analysis. Results: four out of seven radiosensitivity syndrome patients were identified to have an increased cellular radiosensitivity as determined by reduced apoptotic rates after irradiation of their respective LCLs. Comparatively, only two of the five hypersensitive cancer patients were clearly identified by reduced apoptotic rates. Spontaneous apoptotic rates were very homogeneous among all 39 samples from controls and patients, while lymphocytes of all cancer patients showed significantly lower radiation-induced rates. Conclusion: only a subgroup of hypersensitive patients may be identified by reduction of radiation-induced apoptotic rate. It is concluded that the hypothesis according to which hypersensitive cells have reduced levels of apoptosis is only conditionally true. The authors suggest that this

  5. Differential Adaptive Response and Survival of Salmonella enterica Serovar Enteritidis Planktonic and Biofilm Cells Exposed to Benzalkonium Chloride▿

    Science.gov (United States)

    Mangalappalli-Illathu, Anil K.; Vidović, Sinisa; Korber, Darren R.

    2008-01-01

    This study examined the adaptive response and survival of planktonic and biofilm phenotypes of Salmonella enterica serovar Enteritidis adapted to benzalkonium chloride (BC). Planktonic cells and biofilms were continuously exposed to 1 μg ml−1 of BC for 144 h. The proportion of BC-adapted biofilm cells able to survive a lethal BC treatment (30 μg ml−1) was significantly higher (4.6-fold) than that of BC-adapted planktonic cells. Similarly, there were 18.3-fold more survivors among the BC-adapted biofilm cells than among their nonadapted (i.e., without prior BC exposure) cell counterparts at the lethal BC concentration, and this value was significantly higher than the value for BC-adapted planktonic cells versus nonadapted cells (3.2-fold). A significantly higher (P < 0.05) proportion of surviving cells was noticed among BC-adapted biofilm cells relative to BC-adapted planktonic cells following a 10-min heat shock at 55°C. Fatty acid composition was significantly influenced by phenotype (planktonic cells or biofilm) and BC adaptation. Cell surface roughness of biofilm cells was also significantly greater (P < 0.05) than that of planktonic cells. Key proteins upregulated in BC-adapted planktonic and biofilm cells included CspA, TrxA, Tsf, YjgF, and a probable peroxidase, STY0440. Nine and 17 unique proteins were upregulated in BC-adapted planktonic and biofilm cells, respectively. These results suggest that enhanced biofilm-specific upregulation of 17 unique proteins, along with the increased expression of CspA, TrxA, Tsf, YjgF, and a probable peroxidase, phenotype-specific alterations in cell surface roughness, and a shift in fatty acid composition conferred enhanced survival to the BC-adapted biofilm cell population relative to their BC-adapted planktonic cell counterparts. PMID:18663028

  6. HIV-specific cytotoxic T-cell activity in an HIV-exposed but uninfected infant.

    Science.gov (United States)

    Rowland-Jones, S L; Nixon, D F; Aldhous, M C; Gotch, F; Ariyoshi, K; Hallam, N; Kroll, J S; Froebel, K; McMichael, A

    1993-04-03

    The factors necessary for protective immunity against HIV-1 are unknown. Important information about these factors should come from study of people at high risk of HIV infection who have not apparently become infected. Among these are the estimated 60-85% of children who may be exposed in utero or perinatally to HIV-1 but do not become infected. We observed the transient appearance of HIV-specific cytotoxic T-lymphocyte (CTL) activity in a baby born to HIV-1-infected parents, in whom all standard markers of infection remained negative. These findings suggest that HIV-specific CTLs may be a marker for recently exposed, but uninfected, individuals.

  7. Changes of cell factor in bronchoalveolar lavage fluid in rats exposed to silica

    Institute of Scientific and Technical Information of China (English)

    张玮

    2014-01-01

    Objective To investigate the changes in the levels of inflammatory cytokines in bronchoalveolar lavage fluid(BALF)in rats exposed to silica dust.Methods Experimental rats were randomly divided into control group and three experimental groups(doses of dust:15,30,and 60mg/ml),with 42 rats in each group.Each rat in the control group was treated with 1 ml of normal saline by intratracheal instillation,while each rat in the experimental groups was exposed to 1

  8. Phenotypic malignant changes and untargeted lipidomic analysis of long-term exposed prostate cancer cells to endocrine disruptors

    Energy Technology Data Exchange (ETDEWEB)

    Bedia, Carmen, E-mail: carmen.bedia@idaea.csic.es; Dalmau, Núria, E-mail: nuria.dalmau@idaea.csic.es; Jaumot, Joaquim, E-mail: joaquim.jaumot@idaea.csic.es; Tauler, Romà, E-mail: roma.tauler@idaea.csic.es

    2015-07-15

    Endocrine disruptors (EDs) are a class of environmental toxic molecules able to interfere with the normal hormone metabolism. Numerous studies involve EDs exposure to initiation and development of cancers, including prostate cancer. In this work, three different EDs (aldrin, aroclor 1254 and chlorpyrifos (CPF)) were investigated as potential inducers of a malignant phenotype in DU145 prostate cancer cells after a chronic exposure. Epithelial to mesenchymal transition (EMT) induction, proliferation, migration, colony formation and release of metalloproteinase 2 (MMP-2) were analyzed in 50-day exposed cells to the selected EDs. As a result, aldrin and CPF exposure led to an EMT induction (loss of 16% and 14% of E-cadherin levels, respectively, compared to the unexposed cells). Aroclor and CPF presented an increased migration (134% and 126%, respectively), colony formation (204% and 144%, respectively) and MMP-2 release (137% in both cases) compared to the unexposed cells. An untargeted lipidomic analysis was performed to decipher the lipids involved in the observed transformations. As general results, aldrin exposure showed a global decrease in phospholipids and sphingolipids, and aroclor and CPF showed an increase of certain phospholipids, glycosphingolipids as well as a remarkable increase of some cardiolipin species. Furthermore, the three exposures resulted in an increase of some triglyceride species. In conclusion, some significant changes in lipids were identified and thus we postulate that some lipid compounds and lipid metabolic pathways could be involved in the acquisition of the malignant phenotype in exposed prostate cancer cells to the selected EDs. - Highlights: • Aldrin, aroclor and chlorpyrifos induced an aggressive phenotype in DU145 cells. • An untargeted lipidomic analysis has been performed on chronic exposed cells. • Lipidomic results showed changes in specific lipid species under chronic exposure. • These lipids may have a role in the

  9. Erythrophagocytosis of Lead-Exposed Erythrocytes by Renal Tubular Cells: Possible Role in Lead-Induced Nephrotoxicity

    OpenAIRE

    Kwon, So-Youn; Bae, Ok-Nam; Noh, Ji-Yoon; Kim, Keunyoung; Kang, Seojin; Shin, Young-Jun; Lim, Kyung-Min; Chung, Jin-Ho

    2014-01-01

    Background: Nephrotoxicity associated with lead poisoning has been frequently reported in epidemiological studies, but the underlying mechanisms have not been fully described. Objectives: We examined the role of erythrocytes, one of the major lead reservoirs, in lead-associated nephrotoxicity. Methods and results: Co-incubation of lead-exposed human erythrocytes with HK-2 human renal proximal tubular cells resulted in renal tubular cytotoxicity, suggesting a role of erythrocytes in lead-induc...

  10. Detection of Sperm DNA Damage in Workers Exposed to Benzene by Modified Single Cell Gel Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Bo SONG; Zhi-ming CAI; Xin LI; Li-xia DENG; Qiao ZHANG; Lu-kang ZHENG

    2005-01-01

    Objective To assess the effect of benzene on sperm DNA damageMethods Twenty-seven benzene-exposed workers were selected as exposed groupand 35 normal sperm donors as control group. Air concentration of benzene series inworkshop was determined by gas chromatography. As an internal exposure dose ofbenzene, the concentration of trans, trans-muconic acid (ttMA) was determined byhigh performance liquid chromatography. DNA was detected by modified single cellgel electrophoresis (SCGE).Results The air concentrations of benzene, toluene and xylene at the workplace were86.49 ± 2.83 mg/m3, 97.20 ±3.52 mg/m3 and 97.45 ±2.10 mg/m3, respectively.Urinary ttMA in exposed group (1.040 ± 0.617 mg/L) was significantly higher thanthat of control group (0.819 ± 0.157 mg/L). The percentage of head DNA, determinedby modified SCGE method, significantly decreased in the exposed group (n=13, 70.18%± 7.36%) compared with the control (n=16, 90.62% ± 2.94%)(P<0.001).Conclusion The modified SCGE method can be used to investigate the damage ofsperm DNA. As genotoxin and reprotoxins, benzene had direct effect on the germ cellsduring the spermatogenesiss.

  11. Cell viability, reactive oxygen species, apoptosis, and necrosis in myoblast cultures exposed to low-level infrared laser.

    Science.gov (United States)

    Alexsandra da Silva Neto Trajano, Larissa; da Silva, Camila Luna; de Carvalho, Simone Nunes; Cortez, Erika; Mencalha, André Luiz; de Souza da Fonseca, Adenilson; Stumbo, Ana Carolina

    2016-07-01

    Low-level infrared laser is considered safe and effective for treatment of muscle injuries. However, the mechanism involved on beneficial effects of laser therapy are not understood. The aim was to evaluate cell viability, reactive oxygen species, apoptosis, and necrosis in myoblast cultures exposed to low-level infrared laser at therapeutic fluences. C2C12 myoblast cultures at different (2 and 10 %) fetal bovine serum (FBS) concentrations were exposed to low-level infrared laser (808 nm, 100 mW) at different fluences (10, 35, and 70 J/cm(2)) and evaluated after 24, 48, and 72 h. Cell viability was evaluated by WST-1 assay; reactive oxygen species (ROS), apoptosis, and necrosis were evaluated by flow cytometry. Cell viability was decreased atthe lowest FBS concentration. Laser exposure increased the cell viability in myoblast cultures at 2 % FBS after 48 and 72 h, but no significant increase in ROS was observed. Apoptosis was decreased at the higher fluence and necrosis was increased at lower fluence in myoblast cultures after 24 h of laser exposure at 2 % FBS. No laser-induced alterations were obtained at 10 % FBS. Results show that level of reactive oxygen species is not altered, at least to those evaluated in this study, but low-level infrared laser exposure affects cell viability, apoptosis, and necrosis in myoblast cultures depending on laser fluence and physiologic conditions of cells.

  12. Mutagenic adaptive response to high-LET radiation in human lymphoblastoid cells exposed to X-rays.

    Science.gov (United States)

    Varès, Guillaume; Wang, Bing; Tanaka, Kaoru; Kakimoto, Ayana; Eguchi-Kasai, Kyomi; Nenoi, Mitsuru

    2011-01-10

    The ability of cells to adapt low-dose or low-dose rate radiation is well known. High-LET radiation has unique characteristics, and the data concerning low doses effects and high-LET radiation remain fragmented. In this study, we assessed in vitro the ability of low doses of X-rays to induce an adaptive response (AR) to a subsequent challenging dose of heavy-ion radiation. Lymphoblastoid cells (TK6, AHH-1, NH32) were exposed to priming 0.02-0.1Gy X-rays, followed 6h later by challenging 1Gy heavy-ion radiation (carbon-ion: 20 and 40keV/μm, neon-ion: 150keV/μm). Pre-exposure of p53-competent cells resulted in decreased mutation frequencies at hypoxanthine-guanine phosphoribosyl transferase locus and different H2AX phosphorylation kinetics, as compared to cells exposed to challenging radiation alone. This phenomenon did not seem to be linked with cell cycle effects or radiation-induced apoptosis. Taken together, our results suggested the existence of an AR to mutagenic effects of heavy-ion radiation in lymphoblastoid cells and the involvement of double-strand break repair mechanisms.

  13. Evaluation of DNA damage in agricultural workers exposed to pesticides using single cell gel electrophoresis (comet assay

    Directory of Open Access Journals (Sweden)

    Raminderjeet Kaur

    2011-01-01

    Full Text Available Background : Pesticides are used in agriculture to protect crops, but they pose a potential risk to farmers and environment. The aim of the present study is to investigate the relation between the occupational exposure to various pesticides and the presence of DNA damage. Materials and Methods : Blood samples of 210 exposed workers (after a day of intense spraying and 50 control subjects belonging to various districts of Punjab (India were evaluated using Comet assay. Sixty workers who showed DNA damage were selected for follow up at 5-6 months after the first sampling during a low or null spraying period. Results : Significant differences were found in DNA damage between freshly exposed workers and controls and freshly exposed and followed up cases. There was significant increase in the comet parameters viz. mean comet tail length and frequency of cells showing migration in exposed workers as compared to controls (72.22 ± 20.76 vs. 46.92 ± 8.17, P<0.001; 31.79 vs. 5.77, P<0.001. In the second samples, followed up cases showed significant decrease in frequency of damaged cells as compared to freshly exposed workers of first sampling (P<0.05. The confounding factors such as variable duration of pesticide exposure, age, smoking, drinking and dietary habits etc which were expected to modulate the damage, were instead found to have no significant effect on DNA fragmentation. Conclusion : The evidence of a genetic hazard related to exposure resulting from the intensive use of pesticides stresses the need for educational programs for agricultural workers to reduce the use of chemicals in agriculture.

  14. Microcephalin and pericentrin regulate mitotic entry via centrosome-associated Chk1

    DEFF Research Database (Denmark)

    Tibelius, Alexandra; Marhold, Joachim; Zentgraf, Hanswalter

    2009-01-01

    in microcephalin (MCPH1), cells from patients with Seckel syndrome and MOPD II harbor mutations in ataxia telangiectasia and Rad3 related (ATR) or pericentrin (PCNT), leading to disturbed ATR signaling. In this study, we show that a lack of MCPH1 or PCNT results in a loss of Chk1 from centrosomes with subsequently...

  15. Loss of ATM kinase activity leads to embryonic lethality in mice

    DEFF Research Database (Denmark)

    Daniel, J.A.; Pellegrini, M.; Filsuf, D.

    2012-01-01

    Ataxia telangiectasia (A-T) mutated (ATM) is a key deoxyribonucleic acid (DNA) damage signaling kinase that regulates DNA repair, cell cycle checkpoints, and apoptosis. The majority of patients with A-T, a cancer-prone neurodegenerative disease, present with null mutations in Atm. To determine...

  16. Sequence Classification: 889230 [

    Lifescience Database Archive (English)

    Full Text Available , primarily involved in telomere length regulation; contributes to cell cycle checkpoint control in response to DNA damage; functiona...lly redundant with Mec1p; homolog of human ataxia telangiectasia (ATM) gene; Tel1p || http://www.ncbi.nlm.nih.gov/protein/6319383 ...

  17. A new method specifically designed to expose cells isolated in vitro to radon and its decay products.

    Science.gov (United States)

    Petitot, F; Morlier, J P; Debroche, M; Pineau, J F; Chevillard, S

    2002-06-01

    A system was set up to provide direct exposure of cells cultured in vitro to radon and its decay products. Radon gas emanating from a uranium source was introduced at a measured concentration in a closed 10-m(3) exposure chamber. Cells were cultured on the microporous membrane of an insert that was floating over the culture medium in a six-well cluster plate. Plates with cells were placed in an open thermoregulated bath within the chamber. Under these conditions, cells were irradiated by direct deposition of radon and radon decay products. During exposure, all parameters, including radon gas concentrations, decay product activities, and potential alpha-particle energy concentrations, were determined by periodic air-grab samplings inside the chamber. The energy spectrum of deposited decay products was characterized. An estimation of alpha-particle flux density on the area containing cells was performed using CR-39 detector films that were exposed in cell-free wells during the cell exposure. The number of alpha-particle traversals per cell was deduced both from the mean number of CR-39 tracks per surface unit and from measurements of entire cells or nuclear surfaces. This paper describes the design of experiment, the dosimetry of radon and radon decay product, and the procedures for aerosol measurements. Our preliminary data show the usefulness of the in vitro cell culture approach to the study of the early cellular effects of radon and its decay products.

  18. Associations of ATM Polymorphisms With Survival in Advanced Esophageal Squamous Cell Carcinoma Patients Receiving Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Du, Zhongli [State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Department of Etiology and Carcinogenesis (Beijing Key Laboratory for Carcinogenesis and Cancer Prevention), Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Zhang, Wencheng [Department of Radiation Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Zhou, Yuling; Yu, Dianke; Chen, Xiabin; Chang, Jiang; Qiao, Yan; Zhang, Meng; Huang, Ying; Wu, Chen [State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Department of Etiology and Carcinogenesis (Beijing Key Laboratory for Carcinogenesis and Cancer Prevention), Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Xiao, Zefen, E-mail: xiaozefen@sina.com [Department of Radiation Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Tan, Wen, E-mail: tanwen@cicams.ac.cn [State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Department of Etiology and Carcinogenesis (Beijing Key Laboratory for Carcinogenesis and Cancer Prevention), Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); and others

    2015-09-01

    Purpose: To investigate whether single nucleotide polymorphisms (SNPs) in the ataxia telangiectasia mutated (ATM) gene are associated with survival in patients with esophageal squamous cell carcinoma (ESCC) receiving radiation therapy or chemoradiation therapy or surgery only. Methods and Materials: Four tagSNPs of ATM were genotyped in 412 individuals with clinical stage III or IV ESCC receiving radiation therapy or chemoradiation therapy, and in 388 individuals with stage I, II, or III ESCC treated with surgery only. Overall survival time of ESCC among different genotypes was estimated by Kaplan-Meier plot, and the significance was examined by log-rank test. The hazard ratios (HRs) and 95% confidence intervals (CIs) for death from ESCC among different genotypes were computed by a Cox proportional regression model. Results: We found 2 SNPs, rs664143 and rs664677, associated with survival time of ESCC patients receiving radiation therapy. Individuals with the rs664143A allele had poorer median survival time compared with the rs664143G allele (14.0 vs 20.0 months), with the HR for death being 1.45 (95% CI 1.12-1.89). Individuals with the rs664677C allele also had worse median survival time than those with the rs664677T allele (14.0 vs 23.5 months), with the HR of 1.57 (95% CI 1.18-2.08). Stratified analysis showed that these associations were present in both stage III and IV cancer and different radiation therapy techniques. Significant associations were also found between the SNPs and locosregional progression or progression-free survival. No association between these SNPs and survival time was detected in ESCC patients treated with surgery only. Conclusion: These results suggest that the ATM polymorphisms might serve as independent biomarkers for predicting prognosis in ESCC patients receiving radiation therapy.

  19. Increased frequency of spontaneous neoplastic transformation in progeny of bystander cells from cultures exposed to densely ionizing radiation.

    Directory of Open Access Journals (Sweden)

    Manuela Buonanno

    Full Text Available An increased risk of carcinogenesis caused by exposure to space radiation during prolonged space travel is a limiting factor for human space exploration. Typically, astronauts are exposed to low fluences of ionizing particles that target only a few cells in a tissue at any one time. The propagation of stressful effects from irradiated to neighboring bystander cells and their transmission to progeny cells would be of importance in estimates of the health risks of exposure to space radiation. With relevance to the risk of carcinogenesis, we investigated, in model C3H 10T½ mouse embryo fibroblasts (MEFs, modulation of the spontaneous frequency of neoplastic transformation in the progeny of bystander MEFs that had been in co-culture 10 population doublings earlier with MEFs exposed to moderate doses of densely ionizing iron ions (1 GeV/nucleon or sparsely ionizing protons (1 GeV. An increase (P<0.05 in neoplastic transformation frequency, likely mediated by intercellular communication through gap junctions, was observed in the progeny of bystander cells that had been in co-culture with cells irradiated with iron ions, but not with protons.

  20. Parvovirus B19 NS1 protein induces cell cycle arrest at G2-phase by activating the ATR-CDC25C-CDK1 pathway

    Science.gov (United States)

    Xu, Peng; Zhou, Zhe; Xiong, Min; Zou, Wei; Deng, Xuefeng; Ganaie, Safder S.; Peng, Jianxin; Liu, Kaiyu; Wang, Shengqi; Ye, Shui Qing

    2017-01-01

    Human parvovirus B19 (B19V) infection of primary human erythroid progenitor cells (EPCs) arrests infected cells at both late S-phase and G2-phase, which contain 4N DNA. B19V infection induces a DNA damage response (DDR) that facilitates viral DNA replication but is dispensable for cell cycle arrest at G2-phase; however, a putative C-terminal transactivation domain (TAD2) within NS1 is responsible for G2-phase arrest. To fully understand the mechanism underlying B19V NS1-induced G2-phase arrest, we established two doxycycline-inducible B19V-permissive UT7/Epo-S1 cell lines that express NS1 or NS1mTAD2, and examined the function of the TAD2 domain during G2-phase arrest. The results confirm that the NS1 TAD2 domain plays a pivotal role in NS1-induced G2-phase arrest. Mechanistically, NS1 transactivated cellular gene expression through the TAD2 domain, which was itself responsible for ATR (ataxia-telangiectasia mutated and Rad3-related) activation. Activated ATR phosphorylated CDC25C at serine 216, which in turn inactivated the cyclin B/CDK1 complex without affecting nuclear import of the complex. Importantly, we found that the ATR-CHK1-CDC25C-CDK1 pathway was activated during B19V infection of EPCs, and that ATR activation played an important role in B19V infection-induced G2-phase arrest. PMID:28264028

  1. Naphthalimides Induce G2 Arrest Through the ATM-Activated Chk2-Executed Pathway in HCT116 Cells

    Directory of Open Access Journals (Sweden)

    Hong Zhu

    2009-11-01

    Full Text Available Naphthalimides, particularly amonafide and 2-(2-dimethylamino-6-thia-2-aza-benzo[def]chrysene-1,3-diones (R16, have been identified to possess anticancer activities and to induce G2-M arrest through inhibiting topoisomerase II accompanied by Chk1 degradation. The current study was designed to precisely dissect the signaling pathway(s responsible for the naphthalimide-induced cell cycle arrest in human colon carcinoma HCT116 cells. Using phosphorylated histone H3 and mitotic protein monoclonal 2 as mitosis markers, we first specified the G2 arrest elicited by the R16 and amonafide. Then, R16 and amonafide were revealed to induce phosphorylation of the DNA damage sensor ataxia telangiectasia-mutated (ATM responding to DNA double-strand breaks (DSBs. Inhibition of ATM by both the pharmacological inhibitor caffeine and the specific small interference RNA (siRNA rescued the G2 arrest elicited by R16, indicating its ATM-dependent characteristic. Furthermore, depletion of Chk2, but not Chk1 with their corresponding siRNA, statistically significantly reversed the R16- and amonafide-triggered G2 arrest. Moreover, the naphthalimides phosphorylated Chk2 in an ATM-dependent manner but induced Chk1 degradation. These data indicate that R16 and amonafide preferentially used Chk2 as evidenced by the differential ATM-executed phosphorylation of Chk1 and Chk2. Thus, a clear signaling pathway can be established, in which ATM relays the DNA DSBs signaling triggered by the naphthalimides to the checkpoint kinases, predominantly to Chk2,which finally elicits G2 arrest. The mechanistic elucidation not only favors the development of the naphthalimides as anticancer agents but also provides an alternative strategy of Chk2 inhibition to potentiate the anticancer activities of these agents.

  2. Assessment of micronucleus frequency in exfoliated buccal epithelial cells among fisher folks exposed to mine tailings in Marinduque Island, Philippines

    Institute of Scientific and Technical Information of China (English)

    Elena M Ragragio; Celeste P Belleza; Mark C Narciso; Glenn L Sia Su

    2010-01-01

    Objective:To evaluate the potential toxic effects of mine tailings exposure among the fisher folks residing near and far from the Calancan Bay, Marinduque, using the micronucleus assay as an endpoint.Methods: The fisher folks residing near and far from the Calancan Bay were interviewed and the presence and frequency of cells with micronucleus in exfoliated buccal epithelial cells were examined.Results: Results showed that the prevalence of cells with micronucleus was higher among the fisher folks who were directly exposed to the mine tailings as compared with those fisher folks who reside in a community without exposure of mine tailings and history of mining (P<0.05).Conclusions: The presence and the significant difference in the cells with micronuclei observed near the Calancan Bay could possibly indicate a prolonged chemical stress caused by the toxic heavy metals in the mine tailings and the environment.

  3. ATR controls cellular adaptation to hypoxia through positive regulation of hypoxia-inducible factor 1 (HIF-1) expression.

    Science.gov (United States)

    Fallone, F; Britton, S; Nieto, L; Salles, B; Muller, C

    2013-09-12

    Tumor cells adaptation to severe oxygen deprivation (hypoxia) plays a major role in tumor progression. The transcription factor HIF-1 (hypoxia-inducible factor 1), whose α-subunit is stabilized under hypoxic conditions is a key component of this process. Recent studies showed that two members of the phosphoinositide 3-kinase-related kinases (PIKKs) family, ATM (ataxia telangiectasia mutated) and DNA-PK (DNA-dependent protein kinase), regulate the hypoxic-dependent accumulation of HIF-1. These proteins initiate cellular stress responses when DNA damage occurs. In addition, it has been demonstrated that extreme hypoxia induces a replicative stress resulting in regions of single-stranded DNA at stalled replication forks and the activation of ATR (ataxia telangiectasia and Rad3 related protein), another member of the PIKKs family. Here, we show that even less severe hypoxia (0.1% O2) also induces activation of ATR through replicative stress. Importantly, in using either transiently silenced ATR cells, cells expressing an inactive form of ATR or cells exposed to an ATR inhibitor (CGK733), we demonstrate that hypoxic ATR activation positively regulates the key transcription factor HIF-1 independently of the checkpoint kinase Chk1. We show that ATR kinase activity regulates HIF-1α at the translational level and we find that the elements necessary for the regulation of HIF-1α translation are located within the coding region of HIF-1α mRNA. Finally, by using three independent cellular models, we clearly show that the loss of ATR expression and/or kinase activity results in the decrease of HIF-1 DNA binding under hypoxia and consequently affects protein expression levels of two HIF-1 target genes, GLUT-1 and CAIX. Taken together, our data show a new function for ATR in cellular adaptation to hypoxia through regulation of HIF-1α translation. Our work offers new prospect for cancer therapy using ATR inhibitors with the potential to decrease cellular adaptation in hypoxic

  4. A DP based scheme for real-time reconfiguration of solar cell arrays exposed to dynamic changing inhomogeneous illuminations

    DEFF Research Database (Denmark)

    Shi, Liping; Brehm, Robert

    2016-01-01

    efficiency is drastically reduced. Dynamic real-time reconfiguration of the solar panel array can reduce effects on the output efficiency due to partial shading. This results in a maximized power output of the panel array when exposed to dynamic changing illuminations. The optimal array configuration......The overall energy conversion efficiency of solar cell arrays is highly effected by partial shading effects. Especially for solar panel arrays installed in environments which are exposed to inhomogeneous dynamic changing illuminations such as on roof tops of electrical vehicles the overall system...... with respect to shading patterns can be stated as a combinatorial optimization problem and this paper proposes a dynamic programming (DP) based algorithm which finds the optimal feasible solution to reconfigure the solar panel array for maximum efficiency in real-time with linear time complexity. It is shown...

  5. Effect of Amygdalin on the Proliferation of Hyperoxia-exposed Type Ⅱ Alveolar Epithelial Cells Isolated from Premature Rat

    Institute of Scientific and Technical Information of China (English)

    祝华平; 常立文; 李文斌; 刘汉楚

    2004-01-01

    Summary: The pathogenesis of hyperoxia lung injury and the mechanism of amygdalin on type 2 alveolar epithelial cells (AEC2) isolated from premature rat lungs in vitro were investigated. AEC2 were obtained by primary culture from 20-days fetal rat lung and hyperoxia-exposed cell model was established. Cell proliferating viability was examined by MTT assay after treatment of amygdalin at various concentrations. DNA content and the proliferating cell nuclear antigen (PCNA) protein expression of AEC2 were measured by using flow cytometry and immunocytochemistry respectively after 24 h of hyperoxia exposure or amygdalin treatment. The results showed that hyperoxia inhibited the proliferation and decreased PCNA protein expression in AEC2 of premature rat in vitro. Amygdalin at the concentration range of 50-200 μmol/L stimulated the proliferation of AEC2 in a dose-dependent manner, however, 400 μmol/L amygdalin inhibited the proliferation of AEC2. Amygdalin at the concentration of 200 μmol/L played its best role in facilitating proliferation of AEC2s in vitro and could partially ameliorated the changes of proliferation in hyperoxia exposed AEC2 of premature rat. It has been suggested that hyperoxia inhibited the proliferation of AEC2s of premature rat, which may contribute to hyperoxia lung injury. Amygdalin may play partial protective role in hyperoxia-induced lung injury.

  6. Effect of amygdalin on the proliferation of hyperoxia-exposed type II alveolar epithelial cells isolated from premature rat.

    Science.gov (United States)

    Zhu, Huaping; Chang, Liwen; Li, Wenbin; Liu, Hanchu

    2004-01-01

    The pathogenesis of hyperoxia lung injury and the mechanism of amygdalin on type 2 alveolar epithelial cells (AEC2) isolated from premature rat lungs in vitro were investigated. AEC2 were obtained by primary culture from 20-days fetal rat lung and hyperoxia-exposed cell model was established. Cell proliferating viability was examined by MTT assay after treatment of amygdalin at various concentrations. DNA content and the proliferating cell nuclear antigen (PCNA) protein expression of AEC2 were measured by using flow cytometry and immunocytochemistry respectively after 24 h of hyperoxia exposure or amygdalin treatment. The results showed that hyperoxia inhibited the proliferation and decreased PCNA protein expression in A-EC2 of premature rat in vitro. Amygdalin at the concentration range of 50-200 micromol/L stimulated the proliferation of AEC2 in a dose-dependent manner, however, 400 micromol/L amygdalin inhibited the proliferation of AEC2. Amygdalin at the concentration of 200 micromol/L played its best role in facilitating proliferation of AEC2s in vitro and could partially ameliorated the changes of proliferation in hyperoxia exposed AEC2 of premature rat. It has been suggested that hyperoxia inhibited the proliferation of AEC2s of premature rat, which may contribute to hyperoxia lung injury. Amygdalin may play partial protective role in hyperoxia-induced lung injury.

  7. Global transcriptomic analysis of model human cell lines exposed to surface-modified gold nanoparticles: the effect of surface chemistry

    Science.gov (United States)

    Grzincic, E. M.; Yang, J. A.; Drnevich, J.; Falagan-Lotsch, P.; Murphy, C. J.

    2015-01-01

    Gold nanoparticles (Au NPs) are attractive for biomedical applications not only for their remarkable physical properties, but also for the ease of which their surface chemistry can be manipulated. Many applications involve functionalization of the Au NP surface in order to improve biocompatibility, attach targeting ligands or carry drugs. However, changes in cells exposed to Au NPs of different surface chemistries have been observed, and little is known about how Au NPs and their surface coatings may impact cellular gene expression. The gene expression of two model human cell lines, human dermal fibroblasts (HDF) and prostate cancer cells (PC3) was interrogated by microarray analysis of over 14 000 human genes. The cell lines were exposed to four differently functionalized Au NPs: citrate, poly(allylamine hydrochloride) (PAH), and lipid coatings combined with alkanethiols or PAH. Gene functional annotation categories and weighted gene correlation network analysis were used in order to connect gene expression changes to common cellular functions and to elucidate expression patterns between Au NP samples. Coated Au NPs affect genes implicated in proliferation, angiogenesis, and metabolism in HDF cells, and inflammation, angiogenesis, proliferation apoptosis regulation, survival and invasion in PC3 cells. Subtle changes in surface chemistry, such as the initial net charge, lability of the ligand, and underlying layers greatly influence the degree of expression change and the type of cellular pathway affected.Gold nanoparticles (Au NPs) are attractive for biomedical applications not only for their remarkable physical properties, but also for the ease of which their surface chemistry can be manipulated. Many applications involve functionalization of the Au NP surface in order to improve biocompatibility, attach targeting ligands or carry drugs. However, changes in cells exposed to Au NPs of different surface chemistries have been observed, and little is known about how

  8. Gene expression profiling and pathway analysis of human bronchial epithelial cells exposed to airborne particulate matter collected from Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hong [Department of Environmental Medicine, NYU School of Medicine, Tuxedo, NY (United States); Shamy, Magdy [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Kluz, Thomas; Muñoz, Alexandra B.; Zhong, Mianhua; Laulicht, Freda [Department of Environmental Medicine, NYU School of Medicine, Tuxedo, NY (United States); Alghamdi, Mansour A.; Khoder, Mamdouh I. [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Chen, Lung-Chi [Department of Environmental Medicine, NYU School of Medicine, Tuxedo, NY (United States); Costa, Max, E-mail: Max.Costa@nyumc.org [Department of Environmental Medicine, NYU School of Medicine, Tuxedo, NY (United States)

    2012-12-01

    Epidemiological studies have established a positive correlation between human mortality and increased concentration of airborne particulate matters (PM). However, the mechanisms underlying PM related human diseases, as well as the molecules and pathways mediating the cellular response to PM, are not fully understood. This study aims to investigate the global gene expression changes in human cells exposed to PM{sub 10} and to identify genes and pathways that may contribute to PM related adverse health effects. Human bronchial epithelial cells were exposed to PM{sub 10} collected from Saudi Arabia for 1 or 4 days, and whole transcript expression was profiled using the GeneChip human gene 1.0 ST array. A total of 140 and 230 genes were identified that significantly changed more than 1.5 fold after PM{sub 10} exposure for 1 or 4 days, respectively. Ingenuity Pathway Analysis revealed that different exposure durations triggered distinct pathways. Genes involved in NRF2-mediated response to oxidative stress were up-regulated after 1 day exposure. In contrast, cells exposed for 4 days exhibited significant changes in genes related to cholesterol and lipid synthesis pathways. These observed changes in cellular oxidative stress and lipid synthesis might contribute to PM related respiratory and cardiovascular disease. -- Highlights: ► PM exposure modulated gene expression and associated pathways in BEAS-2B cells. ► One-day exposure to PM induced genes involved in responding to oxidative stress. ► 4-day exposure to PM changed genes associated to cholesterol and lipid synthesis.

  9. Comparison of photovoltaic cell temperatures in modules operating with exposed and enclosed back surfaces

    Science.gov (United States)

    Namkoong, D.; Simon, F. F.

    1981-01-01

    Four different photovoltaic module designs were tested to determine the cell temperature of each design. The cell temperatures were compared to those obtained on identical design, using the same nominal operating cell temperature (NOCT) concept. The results showed that the NOCT procedure does not apply to the enclosed configurations due to continuous transient conditions. The enclosed modules had higher cell temperatures than the open modules, and insulated modules higher than the uninsulated. The severest performance loss - when translated from cell temperatures - 17.5 % for one enclosed, insulated module as a compared to that module mounted openly.

  10. Area Expansivity Moduli of Regenerating Plant Protoplast Cell Walls Exposed to Shear Flows

    Science.gov (United States)

    Fujimura, Yuu; Iino, Masaaki; Watanabe, Ugai

    2005-05-01

    To control the elasticity of the plant cell wall, protoplasts isolated from cultured Catharanthus roseus cells were regenerated in shear flows of 115 s-1 (high shear) and 19.2 s-1 (low shear, as a control). The surface area expansivity modulus and the surface breaking strength of these regenerating protoplasts were measured by a micropipette aspiration technique. Cell wall synthesis was also measured using a cell wall-specific fluorescent dye. High shear exposure for 3 h doubled both the surface area modulus and breaking strength observed under low shear, significantly decreased cell wall synthesis, and roughly quadrupled the moduli of the cell wall. Based on the cell wall synthesis data, we estimated the three-dimensional modulus of the cell wall to be 4.1± 1.2 GPa for the high shear, and 0.35± 0.2 GPa for the low shear condition, using the surface area expansivity modulus divided by the cell wall thickness, which is identical with the Young’s modulus divided by 2(1-σ), where σ is Poisson's ratio. We concluded that high shear exposure considerably strengthens the newly synthesized cell wall.

  11. Ikaros can enhance immune activity though the interaction with Autotaxin in LDIR exposed immune cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Jin; Kim, Min Young; Kim, Ji Young; Kim, Hee Sun; KIm, Cha Soon; Nam, Seon Young; Yang, Kwang Hee; Jin, Young Woo [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd, Seoul (Korea, Republic of)

    2009-04-15

    Ikaros, one of transcription factors, plays major roles in the differentiation and biology of leukocytes, including all classes of lymphocytes (NK, T, and B cells), monocytes/macrophages, and dendritic cells. Ikaros was also shown to regulate early neutrophils differentiation. Therefore, Ikaros appears to be a major determinant in the development and function of immune system. Autotaxin (ATX), which is also called nucleotide pyrophosphatase/phosphodiesterase 2 (NPP2), is an exo-enzyme originally identified as a tumor cell autocrine motility factor. ATX functions as a lysophospholipase D, converting lysophosphatidylcholine (LPC) into the lipid mediator lysophosphatidic acid (LPA). LPA bind together with specific G protein-coupled receptors, which elicit a wide range of cellular responses including the cell proliferation, migration and neurite remodeling. In the Recent report, ATX stimulate human endothelial cells (HUVECs) growth and cytokine production. In our previous study, we showed that low-dose ionizing radiation (LDIR) enhanced the cell proliferation cell coupled with Ikaros phosphorylation. In addition, we found that LDIR increased the expression level of cyclin E and cdk2 protein in IM-9 B lymphoblast cells. In this report, therefore, we try to find Ikaros binding proteins after LDIR in IM-9 lymphoblastic cell lines to examine whether the effects of LDIR induced cell proliferation are one of immune activation responses or not.

  12. Ultrastructural changes in hepatic sinusoidal endothelial cells acutely exposed to colloidal iron.

    Science.gov (United States)

    Bassett, Mark L; Dahlstrom, Jane E; Taylor, Matthew C; Koina, Mark E; Maxwell, Lesley; Francis, Douglas; Jain, Sanjiv; McLean, Allan J

    2003-07-01

    Hepatic sinusoidal endothelial cells form an important interface between the vascular system, represented by the sinusoids, and the space of Disse that surrounds the hepatocyte microvilli. This study aimed to assess the light microscopic and ultrastructural effects of acute exposure of hepatic sinusoidal endothelial cells to colloidal iron by injection of rats with iron polymaltose. Eight minutes after a single intravenous injection of iron polymaltose sinusoidal endothelial cells showed defenestration, and thickening and layering as assessed by transmission electron microscopy. Kupffer cells and stellate cells appeared activated. These changes were not observed in control animals, experiments using equivalent doses of maltose, or experiments using colloidal carbon except for Kupffer cell activation due to colloidal carbon. No significant light microscopic changes were seen in study or control animals. The findings indicate that acute exposure to colloidal iron causes changes in hepatic sinusoidal endothelial cells, stellate cells and Kupffer cells. This may be the result of a direct toxic effect of iron or increased production of reactive oxygen species. These observations suggest a possible mechanism for defenestration of sinusoidal endothelial cells in ageing and in disease states.

  13. Induction of 8-azaguanine resistant mutants in human cultured cells exposed to 31 MeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Fuhrman Conti, A.M.; Francone, G.; Volonte, M.; Gallini, R.E.

    1988-03-01

    The authors report results on the induction of 8-azaguanine (8-AG)-resistant mutants in cultured human cells (EUE) exposed to 31 MeV protons. The spontaneous frequency of mutants was 5.6 +- 0.7 x 10/sup -6/ per viable cell. Gamma rays were taken as reference radiation. Expression times giving the highest frequency of mutants after 31 MeV protons and gamma irradiation were found to be about 10 days for both radiations. The dose-response relationship for mutant induction by protons, as determined at the optimal expression time, was compared to that obtained after gamma rays. The relative biological effectiveness (RBE) is 2.4 +- 0.5, this value being higher than the RBE value determined for cell survival.

  14. MRP1 expression in bronchoalveolar lavage cells in subjects with lung cancer who were chronically exposed to arsenic.

    Science.gov (United States)

    Recio-Vega, Rogelio; Dena-Cazares, Jose Angel; Ramirez-de la Peña, Jorge Luis; Jacobo-Ávila, Antonio; Portales-Castanedo, Arnulfo; Gallegos-Arreola, Martha Patricia; Ocampo-Gomez, Guadalupe; Michel-Ramirez, Gladis

    2015-12-01

    Alteration of multidrug resistance-associated protein-1 (MRP1) expression has been associated with certain lung diseases, and this protein may be pivotal in protecting the lungs against endogenous or exogenous toxic compounds. The aim of this study was to evaluate and compare the expression of MRP1 in bronchoalveolar cells from subjects with and without lung cancer who had been chronically exposed to arsenic through drinking water. MRP1 expression was assessed in bronchoalveolar cells in a total of 102 participants. MRP1 expression was significantly decreased in those with arsenic urinary levels >50 μg/L when compared with the controls. In conclusion, chronic arsenic exposure negatively correlates with the expression of MRP1 in BAL cells in patients with lung cancer.

  15. ATM Polymorphisms Predict Severe Radiation Pneumonitis in Patients With Non-Small Cell Lung Cancer Treated With Definitive Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Huihua [Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan (China); Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liao, Zhongxing, E-mail: zliao@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liu, Zhensheng [Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Xu, Ting [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wang, Qiming; Liu, Hongliang [Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Komaki, Ritsuko; Gomez, Daniel [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wang, Li-E [Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wei, Qingyi, E-mail: qwei@mdanderson.org [Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2013-03-15

    Purpose: The ataxia telangiectasia mutated (ATM) gene mediates detection and repair of DNA damage. We investigated associations between ATM polymorphisms and severe radiation-induced pneumonitis (RP). Methods and Materials: We genotyped 3 potentially functional single nucleotide polymorphisms (SNPs) of ATM (rs1801516 [D1853N/5557G>A], rs189037 [-111G>A] and rs228590) in 362 patients with non-small cell lung cancer (NSCLC), who received definitive (chemo)radiation therapy. The cumulative severe RP probabilities by genotypes were evaluated using the Kaplan-Meier analysis. The associations between severe RP risk and genotypes were assessed by both logistic regression analysis and Cox proportional hazard model with time to event considered. Results: Of 362 patients (72.4% of non-Hispanic whites), 56 (15.5%) experienced grade ≥3 RP. Patients carrying ATM rs189037 AG/GG or rs228590 TT/CT genotypes or rs189037G/rs228590T/rs1801516G (G-T-G) haplotype had a lower risk of severe RP (rs189037: GG/AG vs AA, adjusted hazard ratio [HR] = 0.49, 95% confidence interval [CI], 0.29-0.83, P=.009; rs228590: TT/CT vs CC, HR=0.57, 95% CI, 0.33-0.97, P=.036; haplotype: G-T-G vs A-C-G, HR=0.52, 95% CI, 0.35-0.79, P=.002). Such positive findings remained in non-Hispanic whites. Conclusions: ATM polymorphisms may serve as biomarkers for susceptibility to severe RP in non-Hispanic whites. Large prospective studies are required to confirm our findings.

  16. In Vitro Response of Retinal Pigment Epithelial Cells Exposed to Chitosan Materials Prepared with Different Cross-Linkers

    Directory of Open Access Journals (Sweden)

    Jui-Yang Lai

    2010-12-01

    Full Text Available The interaction between cells and biopolymers is the evaluation indicator of the biocompatibility of materials. The purpose of this work was to examine the responses of retinal pigment epithelial (RPE cells to genipin (GP or glutaraldehyde (GTA cross-linked chitosan by means of cell viability assays, cytokine expression analyses, and apoptosis assays. Evaluations of non-cross-linked chitosan were conducted simultaneously for comparison. Both GP and GTA treated samples with the same extent of cross-linking (around 80% were prepared by varying cross-linking time. Our results showed that GP cross-linking was carried out by either radical polymerization of the monomers or SN2 nucleophilic substitution reaction involving the replacement of the ester group on the monomer with a secondary amide linkage. On the other hand, GTA could react with free amino groups of chitosan, leading to the formation of either the Schiff bases or the Michael-type adducts with terminal aldehydes. The biocompatibility of non-cross-linked chitosan membranes was demonstrated by the absence of any signs of toxicity or inflammation reaction. The present study showed that the ARPE-19 cells exposed to GTA cross-linked chitosan membranes had significantly higher cytotoxicity, interleukin-6 levels, and number of TUNEL-positive nuclei than did those exposed to GP treated samples. In addition, the materials modified with GTA trigger apoptosis at an early stage and may induce toxicity in the RPE cells later. The findings suggest that while the chitosan molecules bridged by GP are satisfactorily cytocompatible, the counterparts treated by GTA do not seem to be tolerated. In terms of material safety, the GP cross-linked chitosan may be compatible with human RPE cells and may have a potential application as delivery carriers in the treatment of posterior segment diseases.

  17. Anti-Inflammatory Effects of Pomegranate Peel Extract in THP-1 Cells Exposed to Particulate Matter PM10

    Directory of Open Access Journals (Sweden)

    Soojin Park

    2016-01-01

    Full Text Available Epidemiological and experimental evidence support health risks associated with the exposure to airborne particulate matter with a diameter of <10 μM (PM10. PM10 stimulates the production of reactive oxygen species (ROS and inflammatory mediators. Thus, we assumed that natural antioxidants might provide health benefits attenuating hazardous effects of PM10. In the present study, we examined the effects of pomegranate peel extract (PPE on THP-1 monocytic cells exposed to PM10. PM10 induced cytotoxicity and the production of ROS. It also increased the expression and secretion of inflammatory cytokines, such as tumor necrosis factor-α (TNF-α, interleukin-1β (IL-1β, and monocyte chemoattractant protein-1 (MCP-1, and cell adhesion molecules, such as intercellular adhesion molecule-1 (ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1. PPE at 10–100 μg mL−1 attenuated the production of ROS and the expression of TNF-α, IL-1β, MCP-1, and ICAM-1, but not VCAM-1, in THP-1 cells stimulated by PM10 (100 μg mL−1. PPE also attenuated the adhesion of PM10-stimulated THP-1 cells to EA.hy926 endothelial cells. PPE constituents, punicalagin and ellagic acid, attenuated PM10-induced monocyte adhesion to endothelial cells, and punicalagin was less cytotoxic compared to ellagic acid. The present study suggests that PPE and punicalagin may be useful in alleviating inflammatory reactions due to particulate matter.

  18. Enhanced proliferation, attachment and osteopontin expression by porcine periodontal cells exposed to Emdogain.

    Science.gov (United States)

    Rincon, J C; Xiao, Y; Young, W G; Bartold, P M

    2005-12-01

    Emdogain (EMD) is an enamel matrix derivative extracted from developing porcine teeth with demonstrated periodontal regenerative potential. EMD has been shown to influence a number of properties of periodontal ligament cells including proliferation, cell attachment and matrix synthesis. To date, the effect of EMD on the epithelial cell rests of Malassez (ERM) is unknown. In this study, periodontal ligament fibroblasts, ERM, alveolar bone cells and gingival fibroblasts were obtained from porcine periodontal ligament, alveolar bone and gingiva. This study investigated, in vitro, the effect of EMD at three concentrations on proliferation, cell attachment and expression of mRNA for two mineralised tissue-related proteins (osteopontin and bone sialoprotein). As for other periodontal cells, the ERM proliferative response was enhanced by EMD. Attachment assays revealed a highly significant increase for ERM and gingival fibroblasts after EMD treatment at all concentrations. This study has also shown that EMD stimulated expression of osteopontin mRNA by ERM and alveolar bone cells. The results from this study provide evidence that EMD enhanced cellular events related with proliferation, attachment and osteopontin mRNA expression by porcine periodontal cells, in a manner consistent with its role in periodontal regenerative therapy.

  19. Cord blood dendritic cell subsets in African newborns exposed to Plasmodium falciparum in utero.

    NARCIS (Netherlands)

    Breitling, L.P.; Fendel, R.; Mordmueller, B.; Adegnika, A.A.; Kremsner, P.G.; Luty, A.J.F.

    2006-01-01

    Placental Plasmodium falciparum infection affects birth outcomes and sensitizes fetal lymphocytes to parasite antigens. We assessed the influence of maternal P. falciparum infection on fetal myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC), analyzing the cord blood of offspring o

  20. Structural damage of chicken red blood cells exposed to platinum nanoparticles and cisplatin

    DEFF Research Database (Denmark)

    Kutwin, Marta; Sawosz, Ewa; Jaworski, Sławomir;

    2014-01-01

    of platinum nanoparticles (NP-Pt) and cisplatin with blood compartments are important for future applications. This study investigated structural damage, cell membrane deformation and haemolysis of chicken embryo red blood cells (RBC) after treatment with cisplatin and NP-Pt. Cisplatin (4 μg/ml) and NP-Pt (2......Side effects and resistance of cancer cells to cisplatin are major drawbacks to its application, and recently, the possibility of replacing cisplatin with nanocompounds has been considered. Most chemotherapeutic agents are administered intravenously, and comparisons between the interactions......,6 μg/ml), when incubated with chicken embryo RBC, were detrimental to cell structure and induced haemolysis. The level of haemolytic injury was increased after cisplatin and NP-Pt treatments compared to the control group. Treatment with cisplatin caused structural damage to cell membranes...

  1. Reduced Neurite Density in Neuronal Cell Cultures Exposed to Serum of Patients with Bipolar Disorder

    Science.gov (United States)

    Wollenhaupt-Aguiar, Bianca; Pfaffenseller, Bianca; Chagas, Vinicius de Saraiva; Castro, Mauro A A; Passos, Ives Cavalcante; Kauer-Sant’Anna, Márcia; Kapczinski, Flavio

    2016-01-01

    Background: Increased inflammatory markers and oxidative stress have been reported in serum among patients with bipolar disorder (BD). The aim of this study is to assess whether biochemical changes in the serum of patients induces neurotoxicity in neuronal cell cultures. Methods: We challenged the retinoic acid-differentiated human neuroblastoma SH-SY5Y cells with the serum of BD patients at early and late stages of illness and assessed neurite density and cell viability as neurotoxic endpoints. Results: Decreased neurite density was found in neurons treated with the serum of patients, mostly patients at late stages of illness. Also, neurons challenged with the serum of late-stage patients showed a significant decrease in cell viability. Conclusions: Our findings showed that the serum of patients with bipolar disorder induced a decrease in neurite density and cell viability in neuronal cultures. PMID:27207915

  2. Transcriptome analysis of the human T lymphocyte cell line Jurkat and human peripheral blood mononuclear cells exposed to deoxynivalenol (DON): New mechanistic insights

    Energy Technology Data Exchange (ETDEWEB)

    Katika, Madhumohan R. [RIKILT-Institute of Food Safety, Wageningen University and Research Centre, Wageningen (Netherlands); Department of Health Risk Analysis and Toxicology, Maastricht University (Netherlands); Netherlands Toxicogenomics Centre (Netherlands); Hendriksen, Peter J.M. [RIKILT-Institute of Food Safety, Wageningen University and Research Centre, Wageningen (Netherlands); Netherlands Toxicogenomics Centre (Netherlands); Shao, Jia [RIKILT-Institute of Food Safety, Wageningen University and Research Centre, Wageningen (Netherlands); Department of Health Risk Analysis and Toxicology, Maastricht University (Netherlands); Netherlands Toxicogenomics Centre (Netherlands); Loveren, Henk van [Department of Health Risk Analysis and Toxicology, Maastricht University (Netherlands); National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Netherlands Toxicogenomics Centre (Netherlands); Peijnenburg, Ad, E-mail: ad.peijnenburg@wur.nl [RIKILT-Institute of Food Safety, Wageningen University and Research Centre, Wageningen (Netherlands); Netherlands Toxicogenomics Centre (Netherlands)

    2012-10-01

    Deoxynivalenol (DON) or vomitoxin is a commonly encountered type-B trichothecene mycotoxin, produced by Fusarium species predominantly found in cereals and grains. DON is known to exert toxic effects on the gastrointestinal, reproductive and neuroendocrine systems, and particularly on the immune system. Depending on dose and exposure time, it can either stimulate or suppress immune function. The main objective of this study was to obtain a deeper insight into DON-induced effects on lymphoid cells. For this, we exposed the human T-lymphocyte cell line Jurkat and human peripheral blood mononuclear cells (PBMCs) to various concentrations of DON for various times and examined gene expression changes by DNA microarray analysis. Jurkat cells were exposed to 0.25 and 0.5 μM DON for 3, 6 and 24 h. Biological interpretation of the microarray data indicated that DON affects various processes in these cells: It upregulates genes involved in ribosome structure and function, RNA/protein synthesis and processing, endoplasmic reticulum (ER) stress, calcium-mediated signaling, mitochondrial function, oxidative stress, the NFAT and NF-κB/TNF-α pathways, T cell activation and apoptosis. The effects of DON on the expression of genes involved in ER stress, NFAT activation and apoptosis were confirmed by qRT-PCR. Other biochemical experiments confirmed that DON activates calcium-dependent proteins such as calcineurin and M-calpain that are known to be involved in T cell activation and apoptosis. Induction of T cell activation was also confirmed by demonstrating that DON activates NFATC1 and induces its translocation from the cytoplasm to the nucleus. For the gene expression profiling of PBMCs, cells were exposed to 2 and 4 μM DON for 6 and 24 h. Comparison of the Jurkat microarray data with those obtained with PBMCs showed that most of the processes affected by DON in the Jurkat cell line were also affected in the PBMCs. -- Highlights: ► The human T cell line Jurkat and human

  3. Rcan1-1L overexpression induces mitochondrial autophagy and improves cell survival in angiotensin II-exposed cardiomyocytes

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Hongyan; Li, Yongqiang; Yan, Lijie; Yang, Haitao; Wu, Jintao; Qian, Peng; Li, Bing; Wang, Shanling, E-mail: shanglingwang@126.com

    2015-07-01

    Mitochondrial autophagy is an important adaptive stress response and can be modulated by various key molecules. A previous study found that the regulator of calcineurin 1-1L (Rcan1-1L) may regulate mitochondrial autophagy and cause mitochondria degradation in neurocytes. However, the effect of Rcan1-1L on cardiomyocytes has not been determined. In the present study, we aimed to investigate the role of Rcan1-1L in angiotensin II (Ang II)-exposed human cardiomyocytes. Above all, Human adult cardiac myocytes (HACMs) were exposed to 200 nmol/L Ang II for 4 days. Enhanced H{sub 2}O{sub 2} production, cytochrome C release and mitochondrial permeability were observed in these cells, which were blocked by valsartan. Consistently, Ang II exposure significantly reduced cardiomyocyte viability. However, transfection of Rcan1-1L vector promoted cell viability and ameliorated the apoptosis caused by Ang II. Rcan1-1L clearly promoted mitochondrial autophagy in HACMs, with elevated autophagy protein (ATG) 5 and light chain 3 (LC3) expression. Transient mitochondrial biogenesis and reduced cytochrome C release was also induced by Rcan1-1L. Additionally, Rcan1-1L significantly inhibited calcineurin/nuclear factor of activated T cells (NFAT) signaling. We thus conclude that Rcan1-1L may play a protective role in Ang II-treated cardiomyocytes through the induction of mitochondrial autophagy, and may be an alternative method of cardiac protection. - Highlights: • Transfection of Rcan1-1L into HACMs promoted cell viability and reduced apoptosis. • Transfection of Rcan1-1L promoted mitochondrial autophagy in HACMs. • Rcan1-1L inhibited the calcineurin/nuclear factor of activated T cells signaling.

  4. DNA damage and apoptosis of endometrial cells cause loss of the early embryo in mice exposed to carbon disulfide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bingzhen [Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan (China); Shen, Chunzi [Centers for Disease Control and Prevention, Zibo (China); Yang, Liu; Li, Chunhui; Yi, Anji [Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan (China); Wang, Zhiping, E-mail: zhipingw@sdu.edu.cn [Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan (China)

    2013-12-01

    Carbon disulfide (CS{sub 2}) may lead to spontaneous abortion and very early pregnancy loss in women exposed in the workplace, but the mechanism remains unclear. We designed an animal model in which gestating Kunming strain mice were exposed to CS{sub 2} via i.p. on gestational day 4 (GD4). We found that the number of implanted blastocysts on GD8 was significantly reduced by each dose of 0.1 LD{sub 50} (157.85 mg/kg), 0.2 LD{sub 50} (315.7 mg/kg) and 0.4 LD{sub 50} (631.4 mg/kg). In addition, both the level of DNA damage and apoptosis rates of endometrial cells on GD4.5 were increased, showed definite dose–response relationships, and inversely related to the number of implanted blastocysts. The expressions of mRNA and protein for the Bax and caspase-3 genes in the uterine tissues on GD4.5 were up-regulated, while the expressions of mRNA and protein for the Bcl-2 gene were dose-dependently down-regulated. Our results indicated that DNA damage and apoptosis of endometrial cells were important reasons for the loss of implanted blastocysts induced by CS{sub 2}. - Highlights: • We built an animal model of CS2 exposure during blastocyst implantation. • Endometrial cells were used in the comet assay to detect DNA damage. • CS2 exposure caused DNA damage and endometrial cell apoptosis. • DNA damage and endometrial cell apoptosis were responsible for embryo loss.

  5. Chemoprotective effects of curcumin in esophageal epithelial cells exposed to bile acids

    Institute of Scientific and Technical Information of China (English)

    Matthew; R; Bower; Harini; S; Aiyer; Robert; CG; Martin

    2010-01-01

    AIM:To investigate the ability of curcumin to counteract the impact of bile acids on gene expression of esophageal epithelial cells.METHODS:An esophageal epithelial cell line(HET1A)was treated with curcumin in the presence of deoxycholic acid.Cell proliferation and viability assays were used to establish an appropriate dose range for curcumin.The combined and individual effects of curcumin and bile acid on cyclooxygenase-2(COX-2)and superoxide dismutase(SOD-1 and SOD-2)gene expression were also assessed.RES...

  6. Glucagon-Like Peptide-1 Triggers Protective Pathways in Pancreatic Beta-Cells Exposed to Glycated Serum

    Directory of Open Access Journals (Sweden)

    Alessandra Puddu

    2013-01-01

    Full Text Available Advanced glycation end products (AGEs might play a pathophysiological role in the development of diabetes and its complications. AGEs negatively affect pancreatic beta-cell function and the expression of transcriptional factors regulating insulin gene. Glucagon-like peptide-1 (GLP-1, an incretin hormone that regulates glucose homeostasis, might counteract the harmful effects of AGEs on the beta cells in culture. The aim of this study was to identify the intracellular mechanisms underlying GLP-1-mediated protection from AGE-induced detrimental activities in pancreatic beta cells. HIT-T15 cells were cultured for 5 days with glycated serum (GS, consisting in a pool of AGEs, in the presence or absence of 10 nmol/L GLP-1. After evaluation of oxidative stress, we determined the expression and subcellular localization of proteins involved in maintaining redox balance and insulin gene expression, such as nuclear factor erythroid-derived 2 (Nrf2, glutathione reductase, PDX-1, and MafA. Then, we investigated proinsulin production. The results showed that GS increased oxidative stress, reduced protein expression of all investigated factors through proteasome activation, and decreased proinsulin content. Furthermore, GS reduced ability of PDX-1 and MafA to bind DNA. Coincubation with GLP-1 reversed these GS-mediated detrimental effects. In conclusion, GLP-1, protecting cells against oxidants, triggers protective intercellular pathways in HIT-T15 cells exposed to GS.

  7. Low-level laser therapy: Effects on human face aged skin and cell viability of HeLa cells exposed to UV radiation

    Directory of Open Access Journals (Sweden)

    Mezghani Sana

    2015-01-01

    Full Text Available Chronic and excessive exposure to UV radiation leads to photoaging and photocarcinogenesis. Adequate protection of the skin against the deleterious effects of UV irradiation is essential. Low-level laser therapy (LLLT is a light source in the red to near-infrared range that has been accepted in a variety of medical applications. In this study, we explored the effect of LLLT in human face aged skin and the cell viability of HeLa cells exposed to UV radiation. We found that LLLT significantly reduced visible wrinkles and the loss of firmness of facial skin in aging subjects. Additionally, treatment of cultured HeLa cells with LLLT prior to or post UVA or UVB exposure significantly protected cells from UV-mediated cell death. All results showed the beneficial effects of LLLT on relieving signs of skin aging and its prevention and protection of the cell viability against UV-induced damage.

  8. Testosterone Protects Mitochondrial Function and Regulates Neuroglobin Expression in Astrocytic Cells Exposed to Glucose Deprivation

    OpenAIRE

    Toro-Urrego, Nicolas; Garcia-Segura, Luis M.; Echeverria, Valentina; Barreto, George E.

    2016-01-01

    Testosterone is a hormone that has been shown to confer neuroprotection from different insults affecting the central nervous system (CNS). Testosterone induces this protection by different mechanisms that include the activation of anti-apoptotic pathways that are directly implicated in neuronal survival. However, little attention has been devoted to its actions on glial cells. In the present study, we have assessed whether testosterone exerts protection in a human astrocyte cell model, the T9...

  9. Proliferation and mRNA expression of absorptive villous cell markers and mineral transporters in prolactin-exposed IEC-6 intestinal crypt cells.

    Science.gov (United States)

    Teerapornpuntakit, Jarinthorn; Wongdee, Kannikar; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Charoenphandhu, Narattaphol

    2012-06-01

    During pregnancy and lactation, prolactin (PRL) enhances intestinal absorption of calcium and other minerals for fetal development and milk production. Although an enhanced absorptive efficiency is believed to mainly result from the upregulation of mineral transporters in the absorptive villous cells, some other possibilities, such as PRL-enhanced crypt cell proliferation and differentiation to increase the absorptive area, have never been ruled out. Here, we investigated cell proliferation and mRNA expression of mineral absorption-related genes in the PRL-exposed IEC-6 crypt cells. As expected, the cell proliferation was not altered by PRL. Inasmuch as the mRNA expressions of villous cell markers, including dipeptidylpeptidase-4, lactase and glucose transporter-5, were not increased, PRL was not likely to enhance crypt cell differentiation into the absorptive villous cells. In contrast to the previous findings in villous cells, PRL was found to downregulate the expression of calbindin-D(9k), claudin-3 and occludin in IEC-6 crypt cells, while having no effect on transient receptor potential vanilloid family channels-5/6, plasma membrane Ca(2+)-ATPase (PMCA)-1b and Na(+)/Ca(2+) exchanger-1 expression. In conclusion, IEC-6 crypt cells did not respond to PRL by increasing proliferation or differentiation into villous cells. The present results thus supported the previous hypothesis that PRL enhanced mineral absorption predominantly by increasing transporter expression and activity in the absorptive villous cells.

  10. Prevention of cell death by the zinc ion chelating agent TPEN in cultured PC12 cells exposed to Oxygen-Glucose Deprivation (OGD).

    Science.gov (United States)

    Liu, Zhao; Huang, Yue-yang; Wang, Yu-xiang; Wang, Hong-gang; Deng, Fei; Heng, Bin; Xie, Lai-hua; Liu, Yan-qiang

    2015-01-01

    To elucidate the role of Zn(2+)-associated glutamate signaling pathway and voltage-dependent outward potassium ion currents in neuronal death induced by hypoxia-ischemia, PC12 cells were exposed to Oxygen-Glucose Deprivation (OGD) solution mimicking the hypoxic-ischemic condition in neuron, and the effect of N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), a specific Zn(2+) chelating agent on OGD-induced neuronal death was assessed in the present study. The cell survival rate, apoptosis status, potassium channel currents, intracellular free glutamate concentration and GluR2 expression in PC12 cells exposed to OGD in the absence or presence of TPEN for different time were investigated. The results showed that OGD exposure increased apoptosis, reduced the cell viability (P concentration of intracellular glutamate (P cells. TPEN partially reversed the influence resulted from OGD. These results suggest that OGD-induced cell apoptosis and/or death is mediated by the alteration in glutamate signaling pathway and the voltage-dependent outward potassium ion currents, while TPEN effectively prevent cell apoptosis and/or death under hypoxic-ischemic condition.

  11. Induction of anchorage-independent growth in primary human cells exposed to protons or HZE ions separately or in dual exposures.

    Science.gov (United States)

    Sutherland, B M; Cuomo, N C; Bennett, P V

    2005-10-01

    Travelers on space missions will be exposed to a complex radiation environment that includes protons and heavy charged particles. Since protons are present at much higher levels than are heavy ions, the most likely scenario for cellular radiation exposure will be proton exposure followed by a hit by a heavy ion. Although the effects of individual ion species on human cells are being investigated extensively, little is known about the effects of exposure to both radiation types. One useful measure of mammalian cell damage is induction of the ability to grow in a semi-solid agar medium highly inhibitory to the growth of normal human cells, termed neoplastic transformation. Using primary human cells, we evaluated induction of soft-agar growth and survival of cells exposed to protons only or to heavy charged particles (600 MeV/nucleon silicon) only as well as of cells exposed to protons followed after a 4-day interval by silicon ions. Both ions alone efficiently transformed the human cells to anchorage-independent growth. Initial experiments indicate that the dose responses for neoplastic transformation of cells exposed to protons and then after 4 days to silicon ions appear similar to that of cells exposed to silicon ions alone.

  12. Whole-Genome Expression Analysis of Human Mesenchymal Stromal Cells Exposed to Ultrasmooth Tantalum vs. Titanium Oxide Surfaces

    DEFF Research Database (Denmark)

    Stiehler, C.; Bunger, C.; Overall, R. W.

    2013-01-01

    Durable osseointegration of metallic bone implants requires that progenitor cells attach, proliferate and differentiate on the implant surface. Previously, we demonstrated superior biocompatibility of human mesenchymal stromal cells (MSCs) cultivated on ultrasmooth tantalum (Ta) as compared...... MSCs cultivated on plain sputter-coated surfaces of Ta or Ti for 1, 2, 4, and 8 days were hybridized to n = 16 U133 Plus 2.0 arrays (Affymetrix(A (R))). Functional annotation, cluster and pathway analyses were performed. The vast majority of genes were differentially regulated after 4 days...... of cultivation and genes upregulated by MSCs exposed to Ta and Ti were predominantly related to the processes of differentiation and transcription, respectively. Functional annotation analysis of the 1,000 temporally most significantly regulated genes suggests earlier cellular differentiation on Ta compared...

  13. Sulindac enhances the killing of cancer cells exposed to oxidative stress.

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    Maria Marchetti

    Full Text Available BACKGROUND: Sulindac is an FDA-approved non-steroidal anti-inflammatory drug (NSAID that affects prostaglandin production by inhibiting cyclooxygenases (COX 1 and 2. Sulindac has also been of interest for more than decade as a chemopreventive for adenomatous colorectal polyps and colon cancer. PRINCIPAL FINDINGS: Pretreatment of human colon and lung cancer cells with sulindac enhances killing by an oxidizing agent such as tert-butyl hydroperoxide (TBHP or hydrogen peroxide. This effect does not involve cyclooxygenase (COX inhibition. However, under the conditions used, there is a significant increase in reactive oxygen species (ROS within the cancer cells and a loss of mitochondrial membrane potential, suggesting that cell death is due to apoptosis, which was confirmed by Tunel assay. In contrast, this enhanced killing was not observed with normal lung or colon cells. SIGNIFICANCE: These results indicate that normal and cancer cells handle oxidative stress in different ways and sulindac can enhance this difference. The combination of sulindac and an oxidizing agent could have therapeutic value.

  14. System for exposing cultured cells to intermittent hypoxia utilizing gas permeable cultureware.

    Science.gov (United States)

    Polak, Jan; Studer-Rabeler, Karen; McHugh, Holly; Hussain, Mehboob A; Shimoda, Larissa A

    2015-07-01

    Tissue intermittent hypoxia (IH) occurs in obstructive sleep apnea, sickle cell anemia, physical exercise and other conditions. Poor gas solubility and slow diffusion through culture media hampers mimicking IH-induced transitions of O(2) in vitro. We aimed to develop a system enabling exposure of cultured cells to IH and to validate such exposure by real-time O(2) measurements and cellular responses. Standard 24-well culture plates and plates with bottoms made from a gas permeable film were placed in a heated cabinet. Desired cycling of O(2) levels was induced using programmable solenoids to purge mixtures of 95% N(2) + 5% CO(2) or 95% O(2) + 5% CO(2). Dissolved oxygen, gas pressure, temperature, and water evaporation were measured during cycling. IH-induced cellular effects were evaluated by hypoxia inducible factor (HIF) and NF-κB luciferase reporters in HEK296 cells and by insulin secretion in rat insulinoma cells. Oxygen cycling in the cabinet was translated into identical changes of O(2) at the well bottom in gas permeable, but not in standard cultureware. Twenty-four hours of IH exposure increased HIF (112%), NF-κB (111%) and insulin secretion (44%). Described system enables reproducible and prolonged IH exposure in cultured cells while controlling for important environmental factors.

  15. DJ1 Expression Downregulates in Neuroblastoma Cells (SK-N-MC Chronically Exposed to HIV-1 and Cocaine.

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    Upal eRoy

    2015-07-01

    Full Text Available Background: HIV-associated neurological disorder (HAND has long been recognized as a consequence of Human Immunodeficiency Virus (HIV infection in the brain. The pathology of HAND gets more complicated with the recreational drug use such as cocaine. Recent studies have suggested multiple genetic influences involved in the pathology of addiction and HAND but only a fraction of the entire genetic risk has been investigated so far. In this regard, role of DJ1 protein (a gene linked to autosomal recessive early-onset Parkinson’s disease in regulating dopamine transmission and reactive oxygen species (ROS production in neuronal cells will be worth investigating in HIV-1 and cocaine exposed microenvironment. Being a very abundant protein in the brain, DJ1 could serve as a potential marker for early detection of HIV-1 and/or cocaine related neurological disorder.Methods: In vitro analysis was done to observe the effect of HIV-1 and/or cocaine on DJ1 protein expression in neuroblastoma cells (SK-N-MC. Gene expression and protein analysis of DJ1 was done on the HIV infected and/or cocaine treated SK-N-MC and compared to untreated cells using real time PCR, Western Blot and flow cytometry.Results: Gene expression and protein analysis indicated that there was a significant decrease in DJ1 expression in SK-N-MC chronically exposed to HIV-1 and/or cocaine.Conclusion: This is the first study to establish that DJ1 expression level in the neuronal cells significantly decreased in presence of HIV-1and/or cocaine indicating oxidative stress level of dopamine neurons.

  16. Nuclear survivin and its relationship to DNA damage repair genes in non-small cell lung cancer investigated using tissue array.

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    Songliu Hu

    Full Text Available PURPOSE: To investigate the predictive role and association of nuclear survivin and the DNA double-strand breaks repair genes in non-small cell lung cancer (NSCLC: DNA-dependent protein kinase catalytic subunit (DNA-PKcs, Ku heterodimeric regulatory complex 70-KD subunit (Ku70 and ataxia-telangiectasia mutated (ATM. METHODS: The protein expression of nuclear survivin, DNA-PKcs, Ku70 and ATM were investigated using immunohistochemistry in tumors from 256 patients with surgically resected NSCLC. Furthermore, we analyzed the correlation between the expression of nuclear survivin, DNA-PKcs, Ku70 and ATM. Univariate and multivariate analyses were performed to determine the prognostic factors that inuenced the overall survival and disease-free survival of NSCLC. RESULTS: The expression of nuclear survivin, DNA-PKcs, Ku70 and ATM was significantly higher in tumor tissues than in normal tissues. By dichotomizing the specimens as expressing low or high levels of nuclear survivin, nuclear survivin correlated significantly with the pathologic stage (P = 0.009 and lymph node status (P = 0.004. The nuclear survivin levels were an independent prognostic factor for both the overall survival and the disease-free survival in univariate and multivariate analyses. Patients with low Ku70 and DNA-PKcs expression had a greater benefit from radiotherapy than patients with high expression of Ku70 (P = 0.012 and DNA-PKcs (P = 0.02. Nuclear survivin expression positively correlated with DNA-PKcs (P<0.001 and Ku70 expression (P<0.001. CONCLUSIONS: Nuclear survivin may be a prognostic factor for overall survival in patients with resected stage I-IIIA NSCLC. DNA-PKcs and Ku70 could predict the effect of radiotherapy in patients with NSCLC. Nuclear survivin may also stimulates DNA double-strand breaks repair by its interaction with DNA-PKcs and Ku70.

  17. The telomeric protein TRF2 is critical for the protection of A549 cells from both telomere erosion and DNA double-strand breaks driven by salvicine.

    Science.gov (United States)

    Zhang, Yong-Wei; Zhang, Zhi-Xiang; Miao, Ze-Hong; Ding, Jian

    2008-03-01

    Telomere repeat binding factor 2 (TRF2) has been increasingly recognized to be involved in DNA damage response and telomere maintenance. Our previous report found that salvicine (SAL), a novel topoisomerase II poison, elicited DNA double-strand breaks and telomere erosion in separate experimental systems. However, it remains to be clarified whether they share a common response to these two events and in particular whether TRF2 is involved in this process. In this study, we found that SAL concurrently induced DNA double-strand breaks, telomeric DNA damage, and telomere erosion in lung carcinoma A549 cells. It was unexpected to find that SAL led to disruption of TRF2, independently of either its transcription or proteasome-mediated degradation. By overexpressing the full-length trf2 gene and transfecting TRF2 small interfering RNAs, we showed that TRF2 protein protected both telomeric and genomic DNA from the SAL-elicited events. It is noteworthy that although both the Ataxia-telangiectasia-mutated (ATM) and the ATM- and Rad3-related (ATR) kinases responded to the SAL-induced DNA damages, only ATR was essential for the telomere erosion. The study also showed that the activated ATR augmented the SAL-triggered TRF2 disruption, whereas TRF2 reduction in turn enhanced ATR function. All of these findings suggest the emerging significance of TRF2 protecting both telomeric DNA and genomic DNA on the one hand and reveal the mutual modulation between ATR and TRF2 in sensing DNA damage signaling during cancer development on the other hand.

  18. p38 MAPK-Mediated Bmi-1 down-regulation and defective proliferation in ATM-deficient neural stem cells can be restored by Akt activation.

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    Jeesun Kim

    Full Text Available A-T (ataxia telangiectasia is a genetic disease caused by a mutation in the Atm (A-T mutated gene that leads to neurodegeneration. Despite an increase in the numbers of studies in this area in recent years, the mechanisms underlying neurodegeneration in human A-T are still poorly understood. Previous studies demonstrated that neural stem cells (NSCs isolated from the subventricular zone (SVZ of Atm(-/- mouse brains show defective self-renewal and proliferation, which is accompanied by activation of chronic p38 mitogen-activated protein kinase (MAPK and a lower level of the polycomb protein Bmi-1. However, the mechanism underlying Bmi-1 down-regulation and its relevance to defective proliferation in Atm(-/- NSCs remained unclear. Here, we show that over-expression of Bmi-1 increases self-renewal and proliferation of Atm(-/- NSCs to normal, indicating that defective proliferation in Atm(-/- NSCs is a consequence of down-regulation of Bmi-1. We also demonstrate that epidermal growth factor (EGF-induced Akt phosphorylation renders Bmi-1 resistant to the proteasomal degradation, leading to its stabilization and accumulation in the nucleus. However, inhibition of the Akt-dependent Bmi-1 stabilizing process by p38 MAPK signaling reduces the levels of Bmi-1. Treatment of the Atm(-/- NSCs with a specific p38 MAPK inhibitor SB203580 extended Bmi-1 posttranscriptional turnover and H2A ubiquitination in Atm(-/- NSCs. Our observations demonstrate the molecular basis underlying the impairment of self-renewal and proliferation in Atm(-/- NSCs through the p38 MAPK-Akt-Bmi-1-p21 signaling pathway.

  19. Morphological changes among hippocampal dentate granule cells exposed to early kindling-epileptogenesis.

    Science.gov (United States)

    Singh, Shatrunjai P; He, Xiaoping; McNamara, James O; Danzer, Steve C

    2013-12-01

    Temporal lobe epilepsy is associated with changes in the morphology of hippocampal dentate granule cells. These changes are evident in numerous models that are associated with substantial neuron loss and spontaneous recurrent seizures. By contrast, previous studies have shown that in the kindling model, it is possible to administer a limited number of stimulations sufficient to produce a lifelong enhanced sensitivity to stimulus evoked seizures without associated spontaneous seizures and minimal neuronal loss. Here we examined whether stimulation of the amygdala sufficient to evoke five convulsive seizures (class IV or greater on Racine's scale) produce morphological changes similar to those observed in models of epilepsy associated with substantial cell loss. The morphology of GFP-expressing granule cells from Thy-1 GFP mice was examined either 1 day or 1 month after the last evoked seizure. Interestingly, significant reductions in dendritic spine density were evident 1 day after the last seizure, the magnitude of which had diminished by 1 month. Further, there was an increase in the thickness of the granule cell layer 1 day after the last evoked seizure, which was absent a month later. We also observed an increase in the area of the proximal axon, which again returned to control levels a month later. No differences in the number of basal dendrites were detected at either time point. These findings demonstrate that the early stages of kindling epileptogenesis produce transient changes in the granule cell body layer thickness, molecular layer spine density, and axon proximal area, but do not produce striking rearrangements of granule cell structure.

  20. Ultrastructural changes of bone marrow cells exposed for xenogenous cerebrospinal fluid

    Directory of Open Access Journals (Sweden)

    Shaymardanova L.R.

    2010-01-01

    Full Text Available Due to the scientifical investigations xenogenous cerebrospinal fluid was considered as possible substance for theproduction of powerful adaptogen of biological origin. One of the representative research in these field demonstrates morphologicaland functional changes of bone marrow as the central hemopoetic and immune organ. The article shows the ultramicroscopicchanges of bone marrow cells after the xenogenous cerebrospinal fluid exposure in Vistar rats of differentage. It was revealed the activation of synthetic processes in bone marrow cells of the first three age groups and exhaustion ofactivating mechanisms in the fourth age group, that was manifested in swelling and destruction of mytochondria, vacuolisationof cytoplasm, invagination of caryolemma.

  1. In vitro measurements of oxygen consumption rates in hTERT-RPE cells exposed to low levels of red light

    Science.gov (United States)

    Wigle, Jeffrey C.; Castellanos, Cherry C.

    2016-03-01

    Exposure to 2.88 J/cm2 of red light induces an adaptive response against a lethal pulse of 2.0 μm laser radiation in hTERT-RPE cells in vitro, but not in a knockdown mutant for vascular endothelial growth factor c (VEGF-C). The generally accepted initiation sequence for photobiomodulation is that absorption of red light by cytochome c oxidase (CCOX) of the electron transport chain increases the binding affinity of CCOX for O2 vs. nitric oxide (NO). This results in displacement of NO by O2 in the active site of CCOX, thereby increasing cellular respiration and intracellular ATP. We've previously reported that red-light exposure induces a small, but consistently reproducible, increase in NO levels in these cells. But the relative importance of NO and oxidative phosphorylation is unclear because little is known about the relative contributions of NO and ATP to the response. However, if NO dissociation from CCOX actually increases oxidative phosphorylation, one should see a corresponding increase in oxygen consumption. A Seahorse Extracellular Flux Analyzer was used to measure oxygen consumption rates (OCR) in normal and mutant cells as a proxy for oxidative phosphorylation. Both basal respiration and maximum respiration rates in normal cells are significantly higher than in the mutant. The normal cells have a significant amount of "excess capacity," whereas the VEGF-C(KD) have little or none. The OCR in exposed normal cells is lower than in unexposed cells when measured immediately after exposure. The exposures used for these experiments had no effect on the OCR in mutant cells.

  2. Nanomimics of host cell membranes block invasion and expose invasive malaria parasites.

    Science.gov (United States)

    Najer, Adrian; Wu, Dalin; Bieri, Andrej; Brand, Françoise; Palivan, Cornelia G; Beck, Hans-Peter; Meier, Wolfgang

    2014-12-23

    The fight against most infectious diseases, including malaria, is often hampered by the emergence of drug resistance and lack or limited efficacies of vaccines. Therefore, new drugs, vaccines, or other strategies to control these diseases are needed. Here, we present an innovative nanotechnological strategy in which the nanostructure itself represents the active substance with no necessity to release compounds to attain therapeutic effect and which might act in a drug- and vaccine-like dual function. Invasion of Plasmodium falciparum parasites into red blood cells was selected as a biological model for the initial validation of this approach. Stable nanomimics-polymersomes presenting receptors required for parasite attachment to host cells-were designed to efficiently interrupt the life cycle of the parasite by inhibiting invasion. A simple way to build nanomimics without postformation modifications was established. First, a block copolymer of the receptor with a hydrophobic polymer was synthesized and then mixed with a polymersome-forming block copolymer. The resulting nanomimics bound parasite-derived ligands involved in the initial attachment to host cells and they efficiently blocked reinvasion of malaria parasites after their egress from host cells in vitro. They exhibited efficacies of more than 2 orders of magnitude higher than the soluble form of the receptor, which can be explained by multivalent interactions of several receptors on one nanomimic with multiple ligands on the infective parasite. In the future, our strategy might offer interesting treatment options for severe malaria or a way to modulate the immune response.

  3. Testosterone Protects Mitochondrial Function and Regulates Neuroglobin Expression in Astrocytic Cells Exposed to Glucose Deprivation

    Science.gov (United States)

    Toro-Urrego, Nicolas; Garcia-Segura, Luis M.; Echeverria, Valentina; Barreto, George E.

    2016-01-01

    Testosterone is a hormone that has been shown to confer neuroprotection from different insults affecting the central nervous system (CNS). Testosterone induces this protection by different mechanisms that include the activation of anti-apoptotic pathways that are directly implicated in neuronal survival. However, little attention has been devoted to its actions on glial cells. In the present study, we have assessed whether testosterone exerts protection in a human astrocyte cell model, the T98G cells. Our results indicate that testosterone improves cell survival and mitochondrial membrane potential and reduces nuclear fragmentation and reactive oxygen species (ROS) generation. These effects were accompanied by a positive regulation of neuroglobin, an oxygen-binding and sensor protein, which may serve as a regulator of ROS and nitrogen reactive species (NOS), and these protective effects of testosterone may be at least in part mediated by estradiol and DHT. In conclusion, these findings suggest that astroglia may mediate some of the protective actions of testosterone in the brain upon pathological conditions. PMID:27445795

  4. Biomonitoring of genotoxic and cytotoxic effects of gingival epithelial cells exposed to digital panoramic radiography

    Directory of Open Access Journals (Sweden)

    Anuradha Pai

    2012-01-01

    Full Text Available Objective: The aim of this study was to evaluate genotoxic and cytotoxic effects of low level ionizing radiation used in digital panoramic radiography on gingival epithelial cells. Materials and Methods: We included 50 healthy individuals advised for digital panoramic radiography for diagnostic purpose were included in this study. Demographic data and personal history of all subjects were recorded in a proforma before the examination. Gingival epithelial cells were obtained by gentle scraping with a modified cytobrush immediately before X-ray exposure and 10 ± 2 days later. Cytological preparations were stained according to the Feulgen/fast green method and analyzed under a light microscope. Micronuclei and degenerative nuclear alterations (pyknosis, karyolysis, karyorrhexis and condensed chromatin were scored. Results: The frequency of formation of micronuclei was not significant with regard to age, gender and after exposure to digital panoramic radiography ( P = 0.276. However this study showed significant increase in the frequencies of nuclear alterations like karyorrhexis, pyknosis, condensed chromatin, karyolysis and indicative of cell death ( P < 0.001. Conclusion: Panoramic radiographic examination does not induce genotoxic effect like micronuclei, but it does induce cytotoxic effects leading to cell death.

  5. Photobiomodulation Protects and Promotes Differentiation of C2C12 Myoblast Cells Exposed to Snake Venom

    Science.gov (United States)

    da Silva, Aline; Vieira, Rodolfo Paula; Mesquita-Ferrari, Raquel Agnelli; Cogo, José Carlos; Zamuner, Stella Regina

    2016-01-01

    Background Snakebites is a neglected disease and in Brazil is considered a serious health problem, with the majority of the snakebites caused by the genus Bothrops. Antivenom therapy and other first-aid treatments do not reverse local myonecrose which is the main sequel caused by the envenomation. Several studies have shown the effectiveness of low level laser (LLL) therapy in reducing local myonecrosis induced by Bothropic venoms, however the mechanism involved in this effect is unknown. In this in vitro study, we aimed to analyze the effect of LLL irradiation against cytotoxicity induced by Bothrops jararacussu venom on myoblast C2C12 cells. Methodology C2C12 were utilized as a model target and were incubated with B. jararacussu venom (12.5 μg/mL) and immediately irradiated with LLL at wavelength of red 685 nm or infrared 830 nm with energy density of 2.0, 4.6 and 7.0 J/cm2. Effects of LLL on cellular responses of venom-induced cytotoxicity were examined, including cell viability, measurement of cell damage and intra and extracellular ATP levels, expression of myogenic regulatory factors, as well as cellular differentiation. Results In non-irradiated cells, the venom caused a decrease in cell viability and a massive release of LDH and CK levels indicating myonecrosis. Infrared and red laser at all energy densities were able to considerably decrease venom-induced cytotoxicity. Laser irradiation induced myoblasts to differentiate into myotubes and this effect was accompanied by up regulation of MyoD and specially myogenin. Moreover, LLL was able to reduce the extracellular while increased the intracellular ATP content after venom exposure. In addition, no difference in the intensity of cytotoxicity was shown by non-irradiated and irradiated venom. Conclusion LLL irradiation caused a protective effect on C2C12 cells against the cytotoxicity caused by B. jararacussu venom and promotes differentiation of these cells by up regulation of myogenic factors. A modulatory

  6. Gene expression profile of human lung epithelial cells chronically exposed to single-walled carbon nanotubes

    Science.gov (United States)

    Chen, Dongquan; Stueckle, Todd A.; Luanpitpong, Sudjit; Rojanasakul, Yon; Lu, Yongju; Wang, Liying

    2015-01-01

    A rapid increase in utility of engineered nanomaterials, including carbon nanotubes (CNTs), has raised a concern over their safety. Based on recent evidence from animal studies, pulmonary exposure of CNTs may lead to nanoparticle accumulation in the deep lung without effective clearance which could interact with local lung cells for a long period of time. Physicochemical similarities of CNTs to asbestos fibers may contribute to their asbestos-like carcinogenic potential after long-term exposure, which has not been well addressed. More studies are needed to identify and predict the carcinogenic potential and mechanisms for promoting their safe use. Our previous study reported a long-term in vitro exposure model for CNT carcinogenicity and showed that 6-month sub-chronic exposure of single-walled carbon nanotubes (SWCNT) causes malignant transformation of human lung epithelial cells. In addition, the transformed cells induced tumor formation in mice and exhibited an apoptosis resistant phenotype, a key characteristic of cancer cells. Although the potential role of p53 in the transformation process was identified, the underlying mechanisms of oncogenesis remain largely undefined. Here, we further examined the gene expression profile by using genome microarrays to profile molecular mechanisms of SWCNT oncogenesis. Based on differentially expressed genes, possible mechanisms of SWCNT-associated apoptosis resistance and oncogenesis were identified, which included activation of pAkt/p53/Bcl-2 signaling axis, increased gene expression of Ras family for cell cycle control, Dsh-mediated Notch 1, and downregulation of apoptotic genes BAX and Noxa. Activated immune responses were among the major changes of biological function. Our findings shed light on potential molecular mechanisms and signaling pathways involved in SWCNT oncogenic potential.

  7. The Morphological and Molecular Changes of Brain Cells Exposed to Direct Current Electric Field Stimulation

    Science.gov (United States)

    Pelletier, Simon J.; Lagacé, Marie; St-Amour, Isabelle; Arsenault, Dany; Cisbani, Giulia; Chabrat, Audrey; Fecteau, Shirley; Lévesque, Martin

    2015-01-01

    Background: The application of low-intensity direct current electric fields has been experimentally used in the clinic to treat a number of brain disorders, predominantly using transcranial direct current stimulation approaches. However, the cellular and molecular changes induced by such treatment remain largely unknown. Methods: Here, we tested various intensities of direct current electric fields (0, 25, 50, and 100V/m) in a well-controlled in vitro environment in order to investigate the responses of neurons, microglia, and astrocytes to this type of stimulation. This included morphological assessments of the cells, viability, as well as shape and fiber outgrowth relative to the orientation of the direct current electric field. We also undertook enzyme-linked immunosorbent assays and western immunoblotting to identify which molecular pathways were affected by direct current electric fields. Results: In response to direct current electric field, neurons developed an elongated cell body shape with neurite outgrowth that was associated with a significant increase in growth associated protein-43. Fetal midbrain dopaminergic explants grown in a collagen gel matrix also showed a reorientation of their neurites towards the cathode. BV2 microglial cells adopted distinct morphological changes with an increase in cyclooxygenase-2 expression, but these were dependent on whether they had already been activated with lipopolysaccharide. Finally, astrocytes displayed elongated cell bodies with cellular filopodia that were oriented perpendicularly to the direct current electric field. Conclusion: We show that cells of the central nervous system can respond to direct current electric fields both in terms of their morphological shape and molecular expression of certain proteins, and this in turn can help us to begin understand the mechanisms underlying the clinical benefits of direct current electric field. PMID:25522422

  8. Distribution of Chromosome Breakpoints in Human Epithelial Cells Exposed to Low- and High-LET Radiation

    Science.gov (United States)

    Hada, Megumi; Zhang, Ye; Cucinotta, Francis A.; Feiveson, Alan; Wu, Honglu

    2010-01-01

    Low-and high-LET radiations produced distinct breakpoint distributions. The difference of the breakpoint distributions between low-and high-LET only appeared in break ends involved in interchromosome exchanges. The breakpoint distributions for break ends participating in intrachromosome exchanges were similar. Gene-rich regions do not necessarily have more chromosome breaks. High-LET appeared to produce long live (data not shown) or longer live breaks that can migrate a longer distance before rejoining with other breaks. Domains occupied by different segments of the chromosomes may be responsible for the breakpoint distribution. The dose responses for interchromosomal exchanges were linear in all four exposures. However, the dose response for intrachromosomal exchanges were none linear. Increasing dose of high dose rate exposure (Fe-ions or -rays) increase the fraction of cells with intrachromosome aberrations, whereas increasing dose of low dose rate exposure (neutrons or -rays) does not affect the fraction of cells with intrachromosome aberrations.

  9. Regulation of SUMO2 Target Proteins by the Proteasome in Human Cells Exposed to Replication Stress

    DEFF Research Database (Denmark)

    Bursomanno, Sara; McGouran, Joanna F; Kessler, Benedikt M

    2015-01-01

    In human cells, SUMO2 is predominantly conjugated to target proteins in response to cellular stress. Previous studies suggested that proteins conjugated to SUMO2, but not to SUMO1, could be regulated by the ubiquitin-mediated proteasome system. Hence, we set out to understand the role of the prot......In human cells, SUMO2 is predominantly conjugated to target proteins in response to cellular stress. Previous studies suggested that proteins conjugated to SUMO2, but not to SUMO1, could be regulated by the ubiquitin-mediated proteasome system. Hence, we set out to understand the role...... of genome instability, which is suggested to drive tumorigenesis and possibly aging, our data will facilitate future functional studies in the fields of DNA metabolism and cancer biology....

  10. CYTOKINESIS-BLOCK MICRONUCLEUS ASSAY IN HUMAN GLIOMA CELLS EXPOSED TO RADIATION

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    Jerzy Slowinski

    2011-05-01

    Full Text Available Biological tests are efficient in reflecting the biological influences of several types of generally harmful exposures. The micronucleus assay is widely used in genotoxicity studies or studies on genomic damage in general. We present methodological aspects of cytokinesis-block micronucleus assay performed in human gliomas irradiated in vitro. Eight human glioblastoma cell lines obtained from DSMZ (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Germany were gamma-irradiated (60Co over a dose range of 0-10 Gy. Cytokinesis-block micronucleus assay was performed to quantitate cytogenetic damage. The cells were fixed directly on dishes, stained with fluorochrome DAPI and evaluated under fluorescent and phase contrast microscope. The micronucleus frequency was expressed as a micronuclei (MN per binucleated cell (BNC ratio, calculated after scoring at least 100 BNC per dish. The frequency of spontaneous MN ranged from 0.17 to 0.613 (mean: 0.29 ± 0.14. After irradiation increase of MN frequency in the range of 0.312 - 2.241 (mean: 0.98 ± 0.68 was found at 10 Gy. Gliomas are extremely heterogenous in regard to cytogenetic effects of irradiation, as shown in this study by cytokinesis-block micronucleus assay. This test is easily performed on irradiated glioma cell lines and can assist in determining their radiosensitivity. However, in order to obtain reliable and reproducible results, precise criteria for MN scoring must be strictly followed. Simultaneous use of fluorescent and phase contrast equipment improves imaging of morphological details and can further optimize MN scoring.

  11. Protective Pleiotropic Effect of Flavonoids on NAD+ Levels in Endothelial Cells Exposed to High Glucose

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    Daniëlle M. P. H. J. Boesten

    2015-01-01

    Full Text Available NAD+ is important for oxidative metabolism by serving as an electron transporter. Hyperglycemia decreases NAD+ levels by activation of the polyol pathway and by overactivation of poly(ADP-ribose-polymerase (PARP. We examined the protective role of three structurally related flavonoids (rutin, quercetin, and flavone during high glucose conditions in an in vitro model using human umbilical vein endothelial cells (HUVECs. Additionally we assessed the ability of these flavonoids to inhibit aldose reductase enzyme activity. We have previously shown that flavonoids can inhibit PARP activation. Extending these studies, we here provide evidence that flavonoids are also able to protect endothelial cells against a high glucose induced decrease in NAD+. In addition, we established that flavonoids are able to inhibit aldose reductase, the key enzyme in the polyol pathway. We conclude that this protective effect of flavonoids on NAD+ levels is a combination of the flavonoids ability to inhibit both PARP activation and aldose reductase enzyme activity. This study shows that flavonoids, by a combination of effects, maintain the redox state of the cell during hyperglycemia. This mode of action enables flavonoids to ameliorate diabetic complications.

  12. MicroRNA-1228(*) inhibit apoptosis in A549 cells exposed to fine particulate matter.

    Science.gov (United States)

    Li, Xiaobo; Ding, Zhen; Zhang, Chengcheng; Zhang, Xin; Meng, Qingtao; Wu, Shenshen; Wang, Shizhi; Yin, Lihong; Pu, Yuepu; Chen, Rui

    2016-05-01

    Studies have reported associations between fine particulate matter (PM2.5) and respiratory disorders; however, the underlying mechanism is not completely clear owing to the complex components of PM2.5. microRNAs (miRNAs) demonstrate tremendous regulation to target genes, which are sensitive to exogenous stimulation, and facilitate the integrative understood of biological responses. Here, significantly modulated miRNA were profiled by miRNA microarray, coupled with bioinformatic analysis; the potential biological function of modulated miRNA were predicted and subsequently validated by cell-based assays. Downregulation of miR-1228-5p (miR-1228(*)) expression in human A549 cells were associated with PM2.5-induced cellular apoptosis through a mitochondria-dependent pathway. Further, overexpression of miR-1228(*) rescued the cellular damages induced by PM2.5. Thus, our results demonstrate that PM2.5-induced A549 apoptosis is initiated by mitochondrial dysfunction and miR-1228(*) could protect A549 cells against apoptosis. The involved pathways and target genes might be used for future mechanistic studies.

  13. Proteomic Analysis of MCF-7 Breast Cancer Cell Line Exposed To Leptin

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    A. Valle

    2011-01-01

    Full Text Available Background: Obesity is a well-known factor risk for breast cancer in postmenopausal women. Circulating leptin levels are increased in obese and it has been suggested to play an important role in mammary tumor formation and progression. To contribute to the understanding of the molecular mechanisms underlying leptin action in breast cancer, our aim was to identify proteins regulated by leptin in MCF-7 human breast cancer cells. Methods: We used two-dimensional gel electrophoresis (2-DE and matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS to identify proteins affected by leptin. Results: Thirty proteins were found differentially expressed in MCF-7 cells after 48 h leptin exposure. Proteins regulated by leptin included proteins previously implicated in breast cancer such as catechol-o-methyltransferase, cathepsin D, hsp27, serine/threonine-protein phosphatase and regulatory proteins of the Ras signaling pathway. Proteins involved in other cellular functions such as stress response, cytosqueleton remodeling and proteins belonging to ubiquitin-proteasome system, were also identified. Furthermore, leptin-treated cells showed a substantial uptake of the serum carrier proteins albumin and alpha-2-HS-glycoprotein. Conclusions: This screening reveals that leptin influences the levels of key proteins involved in breast cancer which opens new avenues for the study of the molecular mechanisms linking obesity to breast cancer.

  14. Photocatalytic Oxidation of Triiodide in UVA-Exposed Dye-Sensitized Solar Cells

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    Matthew Carnie

    2012-01-01

    Full Text Available UVA irradiation of glass mounted dye-sensitized solar cells without UV filtration causes failure within 400 hours of light exposure. The failure mode is shown to relate to consumption of I3−, which is directly related to TiO2 photo-catalysis. The onset of failure is easily determined from electrochemical impedance data where the recombination resistance of the TiO2/electrolyte back reaction drops markedly prior to the onset of degradation. At the point of complete cell failure this impedance value then dramatically increases as there is no longer an interfacial reaction possible between the TiO2 and the I3− depleted electrolyte. Device failure is most rapid for cells under electrical load indicating that the degradation of the electrolyte is related to photogenerated hole production by excitation of the TiO2. Once depleted by UV exposure, the I3− can be regenerated by simple application of a reverse bias which can restore severely UV degraded devices to near original working conditions.

  15. Cord blood dendritic cell subsets in African newborns exposed to Plasmodium falciparum in utero.

    Science.gov (United States)

    Breitling, Lutz P; Fendel, Rolf; Mordmueller, Benjamin; Adegnika, Ayola A; Kremsner, Peter G; Luty, Adrian J F

    2006-10-01

    Placental Plasmodium falciparum infection affects birth outcomes and sensitizes fetal lymphocytes to parasite antigens. We assessed the influence of maternal P. falciparum infection on fetal myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC), analyzing the cord blood of offspring of Gabonese mothers with different infection histories. Cord blood from newborns of mothers with malarial infection at delivery had significantly more mDC than that from nonexposed newborns (P = 0.028) but mDC and pDC HLA-DR expression was unrelated to maternal infection history. Independently of these findings, cord blood mDC and pDC numbers declined significantly as a function of increasing maternal age (P = 0.029 and P = 0.033, respectively). The inducible antigen-specific interleukin-10-producing regulatory-type T-cell population that we have previously detected in cord blood of newborns with prolonged in utero exposure to P. falciparum may directly reflect the altered DC numbers in such neonates, while the maintenance of cord blood DC HLA-DR expression contrasts with that of DC from P. falciparum malaria patients.

  16. Bioinformatic Analysis of Differential Protein Expression in Calu-3 Cells Exposed to Carbon Nanotubes

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    Pin Li

    2013-10-01

    Full Text Available Carbon nanomaterials are widely produced and used in industry, medicine and scientific research. To examine the impact of exposure to nanoparticles on human health, the human airway epithelial cell line, Calu-3, was used to evaluate changes in the cellular proteome that could account for alterations in cellular function of airway epithelia after 24 hexposure to 10 μg/mL and 100 ng/mLof two common carbon nanoparticles, single- and multi-wall carbon nanotubes (SWCNT, MWCNT. After exposure to the nanoparticles, label-free quantitative mass spectrometry (LFQMS was used to study the differential protein expression. Ingenuity Pathway Analysis (IPA was used to conduct a bioinformaticanalysis of proteins identified in LFQMS. Interestingly, after exposure to ahigh concentration (10 mg/mL; 0.4 mg/cm2 of MWCNT or SWCNT, only 8 and 13 proteins, respectively, exhibited changes in abundance. In contrast, the abundance of hundreds of proteins was altered in response to a low concentration (100 ng/mL; 4 ng/cm2 of either CNT. Of the 281 and 282 proteins that were significantly altered in response to MWCNT or SWCNT respectively, 231 proteins were the same. Bioinformatic analyses found that the proteins in common to both nanotubes occurred within the cellular functions of cell death and survival, cell-to-cell signaling and interaction, cellular assembly and organization, cellular growth and proliferation, infectious disease, molecular transport and protein synthesis. The majority of the protein changes represent a decrease in amount suggesting a general stress response to protect cells. The STRING database was used to analyze the various functional protein networks. Interestingly, some proteins like cadherin 1 (CDH1, signal transducer and activator of transcription 1 (STAT1, junction plakoglobin (JUP, and apoptosis-associated speck-like protein containing a CARD (PYCARD, appear in several functional categories and tend to be in the center of the networks. This

  17. Reversible alterations in epithelial cell turnover in digestive gland of winkles (Littorina littorea) exposed to cadmium and their implications for biomarker measurements.

    Science.gov (United States)

    Zaldibar, B; Cancio, I; Marigómez, I

    2007-02-28

    In marine molluscs, the epithelium of the digestive gland is composed of two cell types, namely, digestive and basophilic cells. Under normal physiological conditions digestive cells outnumber basophilic cells, but under different stress situations the composition of the epithelium changes, basophilic cells apparently replace digestive cell. Winkles, Littorina littorea, were exposed to 1.25mg/l Cd for 20 days to provoke cell type replacement. Then, animals were depurated in clean seawater for 10 days to determine whether cell type replacement was reversible. Digestive glands were fixed in Carnoy and paraffin embedded for histological analysis. The volume densities of basophilic cells (Vv(BAS)) and digestive cells (Vv(DIG)) were calculated by stereology on hematoxylin-eosin stained sections. Vv(BAS) increased and Vv(DIG) decreased in Cd-exposed animals. After estimation of cell size and absolute cell numbers, these changes were attributed to digestive cell loss and concomitant basophilic cell hypertrophy but not to increased numbers of basophilic cells. Cell type composition and cell size almost fully returned to normal values after 10-day depuration. Accordingly, PCNA immunohistochemistry demonstrated that proliferating digestive cells were more abundant in winkles exposed to Cd and after 10-day depuration than in control specimens, suggesting that net digestive cell loss was accompanied by increased digestive cell proliferation. Thus, Cd-exposure seems to provoke an enhanced digestive cell turnover in order to cope with Cd detoxification. Intralysosomal accumulation of metals (autometallographied black silver deposits; BSD) was used as a biomarker of exposure to Cd and lysosomal structural changes as an effect biomarker to see whether cell type composition might have any effect on these endpoints. BSD formed around Cd ions, in digestive cell lysosomes of Cd-exposed winkles whereas basophilic cells appeared devoid of them. After depuration, BSD were less

  18. Anatase TiO(2) nanosheets with exposed (001) facets: improved photoelectric conversion efficiency in dye-sensitized solar cells.

    Science.gov (United States)

    Yu, Jiaguo; Fan, Jiajie; Lv, Kangle

    2010-10-01

    Dye-sensitized solar cells (DSSCs) are fabricated based on anatase TiO(2) nanosheets (TiO(2)-NSs) with exposed {001} facets, which were obtained by a simple one-pot hydrothermal route using HF as a morphology controlling agent and Ti(OC(4)H(9))(4) as precursor. The prepared samples were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis absorption spectroscopy and N(2) adsorption-desorption isotherms. The photoelectric conversion performances of TiO(2)-NSs solar cells are also compared with TiO(2) nanoparticles (TiO(2)-NPs) and commercial-grade Degussa P25 TiO(2) nanoparticle (P25) solar cells at the same film thickness, and their photoelectric conversion efficiencies (η) are 4.56, 4.24 and 3.64%, respectively. The enhanced performance of the TiO(2)-NS solar cell is due to their good crystallization, high pore volume, large particle size and enhanced light scattering. The prepared TiO(2) nanosheet film electrode should also find wide-ranging potential applications in various fields including photocatalysis, catalysis, electrochemistry, separation, purification and so on.

  19. Anatase TiO2 nanosheets with exposed (001) facets: improved photoelectric conversion efficiency in dye-sensitized solar cells

    Science.gov (United States)

    Yu, Jiaguo; Fan, Jiajie; Lv, Kangle

    2010-10-01

    Dye-sensitized solar cells (DSSCs) are fabricated based on anatase TiO2 nanosheets (TiO2-NSs) with exposed {001} facets, which were obtained by a simple one-pot hydrothermal route using HF as a morphology controlling agent and Ti(OC4H9)4 as precursor. The prepared samples were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis absorption spectroscopy and N2 adsorption-desorption isotherms. The photoelectric conversion performances of TiO2-NSs solar cells are also compared with TiO2 nanoparticles (TiO2-NPs) and commercial-grade Degussa P25 TiO2 nanoparticle (P25) solar cells at the same film thickness, and their photoelectric conversion efficiencies (η) are 4.56, 4.24 and 3.64%, respectively. The enhanced performance of the TiO2-NS solar cell is due to their good crystallization, high pore volume, large particle size and enhanced light scattering. The prepared TiO2 nanosheet film electrode should also find wide-ranging potential applications in various fields including photocatalysis, catalysis, electrochemistry, separation, purification and so on.

  20. Effect of myeloperoxidase inhibition on gene expression profiles in HL-60 cells exposed to 1,2,4,-benzenetriol.

    Science.gov (United States)

    Miyahara, Emiko; Nishikawa, Takuro; Takeuchi, Toru; Yasuda, Kaori; Okamoto, Yasuhiro; Kawano, Yoshifumi; Horiuchi, Masahisa

    2014-03-20

    While it is known that benzene induces myeloid leukemia in humans, the mechanism has yet to be clarified. Previously, we suggested that myeloperoxidase (MPO) was the key enzyme because it promotes generation of powerful oxidant hypochlorous acid (HOCl) which, reacting with DNA, causes leukemogenesis. In this study, using a whole-human-genome oligonucleotide microarray to clarify the relationships between myelotoxicity of benzene and MPO, we analyzed the genome-wide expression profiles of HL-60 human promyelocytic cell lines exposed to 1,2,4-benzenetriol (BT) with or without MPO inhibition. The microarray analysis revealed that short (1 h) and longer (4 h) exposure to BT changed the expression in HL-60 cells of 1,213 or 1,214 genes associated with transcription, RNA metabolic processes, immune response, apoptosis, cell death, and biosynthetic processes (|Z-score|> 2.0), and that these changes were dramatically lessened by MPO-specific inhibition. The presence of functionally important genes and, specifically, genes related to apoptosis, carcinogenesis, regulation of transcription, immune responses, oxidative stress, and cell-cycle regulation were further validated by real-time RT-PCR. Gene expression profiles along with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation analysis suggest that BT-induced DNA halogenation by MPO is a primary reaction in the leukemogenesis associated with benzene.

  1. Electrochemical monitoring of phytochelatin accumulation in Nicotiana tabacum cells exposed to sub-cytotoxic and cytotoxic levels of cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Fojta, Miroslav [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic)]. E-mail: fojta@ibp.cz; Fojtova, Miloslava [Laboratory of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Havran, Ludek [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Pivonkova, Hana [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Dorcak, Vlastimil [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Sestakova, Ivana [J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejskova 3, 182 23 Prague 8 (Czech Republic)

    2006-02-03

    Cadmium belongs to the most dangerous environmental pollutants among the toxic heavy metals seriously affecting vital functions in both animal and plant cells. It has been previously shown that cadmium ions at 50-100 {mu}M concentrations caused tobacco BY-2 (TBY-2) cells to enter apoptosis within several days of exposure. Phytochelatins (PCs), the 'plant metallothioneins', are cysteine-rich peptides involved in detoxification of heavy metals in plants. The PCs are synthesized in response to the heavy metal exposure. In this paper, we utilized electrochemical analysis to monitor accumulation of PCs in the TBY-2 cells exposed to cadmium ions. Measurements of a characteristic PC signal at mercury electrode in the presence of cobalt ions made it possible to detect changes in the cellular PC levels during the time of cultivation, starting from 30 min after exposure. Upon TBY-2 cultivation in the presence of cytotoxic cadmium concentrations, the PC levels remarkably increased during the pre-apoptotic phase and reached a limiting value at cultivation times coinciding with apoptosis trigger. The PC level observed for a sub-cytotoxic cadmium concentration (10 {mu}M) was about three-times lower than that observed for the 50 or 100 {mu}M cadmium ions after 5 days of exposure. We show that using a simple electrochemical analysis, synthesis of PCs in plant cells can be easily followed in parallel with other tests of the cellular response to the toxic heavy metal stress.

  2. Matrix-degrading and pro-inflammatory changes in human vascular endothelial cells exposed to cigarette smoke condensate.

    Science.gov (United States)

    Nordskog, Brian K; Blixt, Allison D; Morgan, Walter T; Fields, Wanda R; Hellmann, Gary M

    2003-01-01

    Cigarette smoking has been associated with an increase in the severity and prevalence of atherosclerosis in the abdominal aorta. To begin our investigation of this finding, we used an integrated approach combining gene expression profiling, protein analysis, cytokine measurements, and cytotoxicity determinations to examine molecular responses of cultured human aortic and coronary endothelial cells exposed to cigarette smoke condensate (CSC) and nicotine. Exposure of endothelial cells to CSC (30 and 60 microg/mL TPM) for 24 h resulted in minimal cytotoxicity, and the upregulation of genes involved in matrix degradation (MMP-1, MMP-8, and MMP-9), xenobiotic metabolism (HO-1 and CYP1A2), and downregulation of genes involved in cell cycle regulation (including TOP2A, CCNB1, CCNA, CDKN3). Exposure of cells to a high physiological concentration of nicotine resulted in few differentially expressed genes. Immunoblot analysis of proteins selected from genes shown to be differentially regulated by microarray analysis revealed similar responses. Finally, a number of inflammatory cytokines measured in culture media were elevated in response to CSC. Together, these results describe a complex proinflammatory response, possibly mediating the recruitment of leukocytes through cytokine signaling. Additionally, fibrous cap destabilization may be facilitated by matrix metalloproteinase upregulation.

  3. Induction of Cell Death through Alteration of Oxidants and Antioxidants in Epithelial Cells Exposed to High Energy Protons

    Science.gov (United States)

    Ramesh, Govindarajan; Wu, Honglu

    2012-01-01

    Radiation affects several cellular and molecular processes including double strand breakage, modifications of sugar moieties and bases. In outer space, protons are the primary radiation source which poses a range of potential health risks to astronauts. On the other hand, the use of proton radiation for tumor radiation therapy is increasing as it largely spares healthy tissues while killing tumor tissues. Although radiation related research has been conducted extensively, the molecular toxicology and cellular mechanisms affected by proton radiation remain poorly understood. Therefore, in the present study, we irradiated rat epithelial cells (LE) with different doses of protons and investigated their effects on cell proliferation and cell death. Our data showed an inhibition of cell proliferation in proton irradiated cells with a significant dose dependent activation and repression of reactive oxygen species (ROS) and antioxidants, glutathione and superoxide dismutase respectively as compared to control cells. In addition, apoptotic related genes such as caspase-3 and -8 activities were induced in a dose dependent manner with corresponding increased levels of DNA fragmentation in proton irradiated cells than control cells. Together, our results show that proton radiation alters oxidant and antioxidant levels in the cells to activate apoptotic pathway for cell death.

  4. Reactive oxygen species regulated mitochondria-mediated apoptosis in PC12 cells exposed to chlorpyrifos

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Eun [Department of Pharmacology, College of Medicine, Hanyang University, Seoul (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Park, Jae Hyeon [Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul (Korea, Republic of); Shin, In Chul [Department of Pharmacology, College of Medicine, Hanyang University, Seoul (Korea, Republic of); Koh, Hyun Chul, E-mail: hckoh@hanyang.ac.kr [Department of Pharmacology, College of Medicine, Hanyang University, Seoul (Korea, Republic of); Hanyang Biomedical Research Institute, Seoul (Korea, Republic of); Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul (Korea, Republic of)

    2012-09-01

    Reactive oxidative species (ROS) generated by environmental toxicants including pesticides could be one of the factors underlying the neuronal cell damage in neurodegenerative diseases. In this study we found that chlorpyrifos (CPF) induced apoptosis in dopaminergic neuronal components of PC12 cells as demonstrated by the activation of caspases and nuclear condensation. Furthermore, CPF also reduced the tyrosine hydroxylase-positive immunoreactivity in substantia nigra of the rat. In addition, CPF induced inhibition of mitochondrial complex I activity. Importantly, N-acetyl cysteine (NAC) treatment effectively blocked apoptosis via the caspase-9 and caspase-3 pathways while NAC attenuated the inhibition of mitochondrial complex I activity as well as the oxidative metabolism of dopamine (DA). These results demonstrated that CPF-induced apoptosis was involved in mitochondrial dysfunction through the production of ROS. In the response of cellular antioxidant systems to CPF, we found that CPF treatment increased HO-1 expression while the expression of CuZnSOD and MnSOD was reduced. In addition, we found that CPF treatment activated MAPK pathways, including ERK 1/2, the JNK, and the p38 MAP kinase in a time-dependent manner. NAC treatment abolished MAPK phosphorylation caused by CPF, indicating that ROS are upstream signals of MAPK. Interestingly, MAPK inhibitors abolished cytotoxicity and reduced ROS generation by CPF treatment. Our results demonstrate that CPF induced neuronal cell death in part through MAPK activation via ROS generation, suggesting its potential to generate oxidative stress via mitochondrial damage and its involvement in oxidative stress-related neurodegenerative disease. -- Highlights: ► Chlorpyrifos induces apoptosis. ► Chlorpyrifos inhibits mitochondrial complex I activity. ► ROS is involved in chlorpyrifos-induced apoptosis. ► Chlorpyrifos affects cellular antioxidant systems. ► Chlorpyrifos-induced apoptosis mediates activation of MAPK.

  5. Lineage-related cytotoxicity and clonogenic profile of 1,4-benzoquinone-exposed hematopoietic stem and progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Paik Wah [Biomedical Science Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Toxicology Laboratory, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia); Abdul Hamid, Zariyantey, E-mail: zyantey@ukm.edu.my [Biomedical Science Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Toxicology Laboratory, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia); Chan, Kok Meng [Environmental Health and Industrial Safety Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Toxicology Laboratory, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia); Inayat-Hussain, Salmaan Hussain [Environmental Health and Industrial Safety Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Rajab, Nor Fadilah [Biomedical Science Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Toxicology Laboratory, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)

    2015-04-01

    Hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) are sensitive targets for benzene-induced hematotoxicity and leukemogenesis. The impact of benzene exposure on the complex microenvironment of HSCs and HPCs remains elusive. This study aims to investigate the mechanism linking benzene exposure to targeting HSCs and HPCs using phenotypic and clonogenic analyses. Mouse bone marrow (BM) cells were exposed ex vivo to the benzene metabolite, 1,4-benzoquinone (1,4-BQ), for 24 h. Expression of cellular surface antigens for HSC (Sca-1), myeloid (Gr-1, CD11b), and lymphoid (CD45, CD3e) populations were confirmed by flow cytometry. The clonogenicity of cells was studied using the colony-forming unit (CFU) assay for multilineage (CFU-GM and CFU-GEMM) and single-lineage (CFU-E, BFU-E, CFU-G, and CFU-M) progenitors. 1,4-BQ demonstrated concentration-dependent cytotoxicity in mouse BM cells. The percentage of apoptotic cells increased (p < 0.05) following 1,4-BQ exposure. Exposure to 1,4-BQ showed no significant effect on CD3e{sup +} cells but reduced the total counts of Sca-1{sup +}, CD11b{sup +}, Gr-1{sup +}, and CD45{sup +} cells at 7 and 12 μM (p < 0.05). Furthermore, the CFU assay showed reduced (p < 0.05) clonogenicity in 1,4-BQ-treated cells. 1,4-BQ induced CFU-dependent cytotoxicity by significantly inhibiting colony growth for CFU-E, BFU-E, CFU-G, and CFU-M starting at a low concentration of exposure (5 μM); whereas for the CFU-GM and CFU-GEMM, the inhibition of colony growth was remarkable only at 7 and 12 μM of 1,4-BQ, respectively. Taken together, 1,4-BQ caused lineage-related cytotoxicity in mouse HPCs, demonstrating greater toxicity in single-lineage progenitors than in those of multi-lineage. - Highlights: • We examine 1,4-BQ toxicity targeting mouse hematopoietic cell lineages. • 1,4-BQ induces concentration-dependent cytotoxicity in bone marrow (BM) cells. • 1,4-BQ shows lineage-related toxicity on hematopoietic stem and

  6. The transcription factor NFAT5 is required for cyclin expression and cell cycle progression in cells exposed to hypertonic stress.

    Directory of Open Access Journals (Sweden)

    Katherine Drews-Elger

    Full Text Available BACKGROUND: Hypertonicity can perturb cellular functions, induce DNA damage-like responses and inhibit proliferation. The transcription factor NFAT5 induces osmoprotective gene products that allow cells to adapt to sustained hypertonic conditions. Although it is known that NFAT5-deficient lymphocytes and renal medullary cells have reduced proliferative capacity and viability under hypertonic stress, less is understood about the contribution of this factor to DNA damage responses and cell cycle regulation. METHODOLOGY/PRINCIPAL FINDINGS: We have generated conditional knockout mice to obtain NFAT5(-/- T lymphocytes, which we used as a model of proliferating cells to study NFAT5-dependent responses. We show that hypertonicity triggered an early, NFAT5-independent, genotoxic stress-like response with induction of p53, p21 and GADD45, downregulation of cyclins, and cell cycle arrest. This was followed by an NFAT5-dependent adaptive phase in wild-type cells, which induced an osmoprotective gene expression program, downregulated stress markers, resumed cyclin expression and proliferation, and displayed enhanced NFAT5 transcriptional activity in S and G2/M. In contrast, NFAT5(-/- cells failed to induce osmoprotective genes and exhibited poorer viability. Although surviving NFAT5(-/- cells downregulated genotoxic stress markers, they underwent cell cycle arrest in G1/S and G2/M, which was associated with reduced expression of cyclins E1, A2 and B1. We also show that pathologic hypertonicity levels, as occurring in plasma of patients and animal models of osmoregulatory disorders, inhibited the induction of cyclins and aurora B kinase in response to T cell receptor stimulation in fresh NFAT5(-/- lymphocytes. CONCLUSIONS/SIGNIFICANCE: We conclude that NFAT5 facilitates cell proliferation under hypertonic conditions by inducing an osmoadaptive response that enables cells to express fundamental regulators needed for cell cycle progression.

  7. Decline of FoxP3+ Regulatory CD4 T Cells in Peripheral Blood of Children Heavily Exposed to Malaria.

    Directory of Open Access Journals (Sweden)

    Michelle J Boyle

    2015-07-01

    Full Text Available FoxP3+ regulatory CD4 T cells (Tregs help to maintain the delicate balance between pathogen-specific immunity and immune-mediated pathology. Prior studies suggest that Tregs are induced by P. falciparum both in vivo and in vitro; however, the factors influencing Treg homeostasis during acute and chronic infections, and their role in malaria immunopathogenesis, remain unclear. We assessed the frequency and phenotype of Tregs in well-characterized cohorts of children residing in a region of high malaria endemicity in Uganda. We found that both the frequency and absolute numbers of FoxP3+ Tregs in peripheral blood declined markedly with increasing prior malaria incidence. Longitudinal measurements confirmed that this decline occurred only among highly malaria-exposed children. The decline of Tregs from peripheral blood was accompanied by reduced in vitro induction of Tregs by parasite antigen and decreased expression of TNFR2 on Tregs among children who had intense prior exposure to malaria. While Treg frequencies were not associated with protection from malaria, there was a trend toward reduced risk of symptomatic malaria once infected with P. falciparum among children with lower Treg frequencies. These data demonstrate that chronic malaria exposure results in altered Treg homeostasis, which may impact the development of antimalarial immunity in naturally exposed populations.

  8. Surveillance of megakaryocytic function by measurement of CD61-exposing microparticles in allogeneic hematopoietic stem cell recipients.

    Science.gov (United States)

    Rank, Andreas; Nieuwland, Rienk; Delker, Ruth; Pihusch, Verena; Wilkowski, Ralf; Toth, Bettina; Kolb, Hans-Jochem; Pihusch, Rudolf

    2011-01-01

    Increasing evidence suggests that circulating microparticles (MP) exposing CD61 originate predominantly from megakaryocytes. Dramatic changes in megakaryocytic homeostasis are regularly observed following allogeneic hematopoietic stem cell transplantation (HSCT) and associated with transplantation-associated complications. We studied MP plasma levels prospectively in healthy subjects (n = 10) and allogeneic HSCT recipients (n = 19) twice weekly from the start of conditioning therapy up to day 30. A total of 224 measurement points were evaluated. MP were isolated, double-stained with annexin V and anti-CD61, and analyzed by flow cytometry. In uncomplicated HSCT, we found a correlation between platelet and CD61-exposing MP count, which resulted in a constant ratio of MP per platelet. The ratio was increased in patients with active hematological malignancies before transplantation and normalized during conditioning therapy. After take, the MP ratio increased, whereas infections and microangiopathic hemolytic anemia did not affect the ratio. In patients with GvHD, a decreased MP ratio was observed depending on the grade of GvHD, possibly indicating megakaryocytic damage. The MP ratio was able to discriminate between toxic, septic, and GvHD-induced hyperbilirubinemia. We first describe CD61+ MP levels during allogeneic HSCT and postulate that the MP ratio might be a useful biomarker for the surveillance of megakaryocytes during HSCT.

  9. APOPTOSIS Y REPARACION DEL DAÑO CROMOSOMICO DURANTE G2 EN CELULAS DE PACIENTES CON SINDROME DE NIJMEGEN Y ATAXIA - TELANGIECTASIA

    OpenAIRE

    MARCELAIN CUBILLOS, KATHERINE JENNY

    2003-01-01

    El material genético de las células está expuesto a agentes endógenos y exógenos que causan lesiones en su estructura. La presencia de daño en el DNA, en particular, las fracturas bicatenarias, genero una condición de alta inestabilidad genómica, con el consecuente riesgo de transformación oncogénica. Las células cuentan con sistemas que detectan las lesiones en el DNA, los que desencadenan varios eventos río abajo que en su conjunto se denominan "respuesta al daño en el DNA". ...

  10. Characteristics of myeloid differentiation and maturation pathway derived from human hematopoietic stem cells exposed to different linear energy transfer radiation types.

    Directory of Open Access Journals (Sweden)

    Satoru Monzen

    Full Text Available Exposure of hematopoietic stem/progenitor cells (HSPCs to ionizing radiation causes a marked suppression of mature functional blood cell production in a linear energy transfer (LET- and/or dose-dependent manner. However, little information about LET effects on the proliferation and differentiation of HSPCs has been reported. With the aim of characterizing the effects of different types of LET radiations on human myeloid hematopoiesis, in vitro hematopoiesis in Human CD34(+ cells exposed to carbon-ion beams or X-rays was compared. Highly purified CD34(+ cells exposed to each form of radiation were plated onto semi-solid culture for a myeloid progenitor assay. The surviving fractions of total myeloid progenitors, colony-forming cells (CFC, exposed to carbon-ion beams were significantly lower than of those exposed to X-rays, indicating that CFCs are more sensitive to carbon-ion beams (D(0 = 0.65 than to X-rays (D(0 = 1.07. Similar sensitivities were observed in granulocyte-macrophage and erythroid progenitors, respectively. However, the sensitivities of mixed-type progenitors to both radiation types were similar. In liquid culture for 14 days, no significant difference in total numbers of mononuclear cells was observed between non-irradiated control culture and cells exposed to 0.5 Gy X-rays, whereas 0.5 Gy carbon-ion beams suppressed cell proliferation to 4.9% of the control, a level similar to that for cells exposed to 1.5 Gy X-rays. Cell surface antigens associated with terminal maturation, such as CD13, CD14, and CD15, on harvest from the culture of X-ray-exposed cells were almost the same as those from the non-irradiated control culture. X-rays increased the CD235a(+ erythroid-related fraction, whereas carbon-ion beams increased the CD34(+CD38(- primitive cell fraction and the CD13(+CD14(+/-CD15(- fraction. These results suggest that carbon-ion beams inflict severe damage on the clonal growth of myeloid HSPCs, although the intensity of cell

  11. Characteristics of myeloid differentiation and maturation pathway derived from human hematopoietic stem cells exposed to different linear energy transfer radiation types.

    Science.gov (United States)

    Monzen, Satoru; Yoshino, Hironori; Kasai-Eguchi, Kiyomi; Kashiwakura, Ikuo

    2013-01-01

    Exposure of hematopoietic stem/progenitor cells (HSPCs) to ionizing radiation causes a marked suppression of mature functional blood cell production in a linear energy transfer (LET)- and/or dose-dependent manner. However, little information about LET effects on the proliferation and differentiation of HSPCs has been reported. With the aim of characterizing the effects of different types of LET radiations on human myeloid hematopoiesis, in vitro hematopoiesis in Human CD34(+) cells exposed to carbon-ion beams or X-rays was compared. Highly purified CD34(+) cells exposed to each form of radiation were plated onto semi-solid culture for a myeloid progenitor assay. The surviving fractions of total myeloid progenitors, colony-forming cells (CFC), exposed to carbon-ion beams were significantly lower than of those exposed to X-rays, indicating that CFCs are more sensitive to carbon-ion beams (D(0) = 0.65) than to X-rays (D(0) = 1.07). Similar sensitivities were observed in granulocyte-macrophage and erythroid progenitors, respectively. However, the sensitivities of mixed-type progenitors to both radiation types were similar. In liquid culture for 14 days, no significant difference in total numbers of mononuclear cells was observed between non-irradiated control culture and cells exposed to 0.5 Gy X-rays, whereas 0.5 Gy carbon-ion beams suppressed cell proliferation to 4.9% of the control, a level similar to that for cells exposed to 1.5 Gy X-rays. Cell surface antigens associated with terminal maturation, such as CD13, CD14, and CD15, on harvest from the culture of X-ray-exposed cells were almost the same as those from the non-irradiated control culture. X-rays increased the CD235a(+) erythroid-related fraction, whereas carbon-ion beams increased the CD34(+)CD38(-) primitive cell fraction and the CD13(+)CD14(+/-)CD15(-) fraction. These results suggest that carbon-ion beams inflict severe damage on the clonal growth of myeloid HSPCs, although the intensity of cell surface

  12. [Cytogenetic investigations of bone marrow cells from mice exposed onboard biosatellite "Bion-M1"].

    Science.gov (United States)

    Dorozhkina, O V; Ivanov, A A

    2015-01-01

    The results of studying the mitotic activities and chromosomal aberrations in bone marrow cells from C57/BL6N mice with the help of the anaphase technique in 12 hours after completion of the 30-day "Bion-M1" mission and ground-based experiment using flight equipment are presented. A statistically reliable decline of the mitotic activity (0.74%) was found in cells taken from the space flown animals. In the ground-based experiment, a statistically reliable downward trend in proliferative activity (1.37%) was revealed after the comparison with groups of vivarium control (1.46-1.53%). In both experiments mice increased the number of initial mitotic phases (prophase + metaphase) relative to the sum of anaphases and telophases. The number of aberrant mitoses grew reliably in the group of flight animals by 29.7%, whereas in the ground-based experiment an upward trend was insignificant as their number increased up to 2.3% only. In the vivarium controls aberrant mitoses constituted 1.75-1.8%. An increase in chromosomal aberrations was largely due to such abnormalities as fragments. These findings seem to have been a result of summation of the effects of radiation and other stressful factors in space flight.

  13. Osteoblastic differentiation and stress response of human mesenchymal stem cells exposed to alternating current electric fields

    Directory of Open Access Journals (Sweden)

    Kaplan David L

    2011-01-01

    Full Text Available Abstract Background Electric fields are integral to many biological events, from maintaining cellular homeostasis to embryonic development to healing. The application of electric fields offers substantial therapeutic potential, while optimal dosing regimens and the underlying mechanisms responsible for the positive clinical impact are poorly understood. Methods The purpose of this study was to track the differentiation profile and stress response of human bone marrow derived mesenchymal stem cells (hMSCs undergoing osteogenic differentiation during exposure to a 20 mV/cm, 60 kHz electric field. Morphological and biochemical changes were imaged using endogenous two-photon excited fluorescence (TPEF and quantitatively assessed through eccentricity calculations and extraction of the redox ratio from NADH, FAD and lipofuscin contributions. Real time reverse transcriptase-polymerase chain reactions (RT-PCR were used to track osteogenic differentiation markers, namely alkaline phosphatase (ALP and collagen type 1 (col1, and stress response markers, such as heat shock protein 27 (hsp27 and heat shock protein 70 (hsp70. Comparisons of collagen deposition between the stimulated hMSCs and controls were examined through second harmonic generation (SHG imaging. Results Quantitative differences in cell morphology, as described through an eccentricity ratio, were found on days 2 and days 5 (p Conclusions Electrical stimulation is a useful tool to improve hMSC osteogenic differentiation, while heat shock proteins may reveal underlying mechanisms, and optical non-invasive imaging may be used to monitor the induced morphological and biochemical changes.

  14. Cigarette Smoke-Exposed Candida albicans Increased Chitin Production and Modulated Human Fibroblast Cell Responses

    Directory of Open Access Journals (Sweden)

    Humidah Alanazi

    2014-01-01

    Full Text Available The predisposition of cigarette smokers for development of respiratory and oral bacterial infections is well documented. Cigarette smoke can also contribute to yeast infection. The aim of this study was to investigate the effect of cigarette smoke condensate (CSC on C. albicans transition, chitin content, and response to environmental stress and to examine the interaction between CSC-pretreated C. albicans and normal human gingival fibroblasts. Following exposure to CSC, C. albicans transition from blastospore to hyphal form increased. CSC-pretreated yeast cells became significantly (P<0.01 sensitive to oxidation but significantly (P<0.01 resistant to both osmotic and heat stress. CSC-pretreated C. albicans expressed high levels of chitin, with 2- to 8-fold recorded under hyphal conditions. CSC-pretreated C. albicans adhered better to the gingival fibroblasts, proliferated almost three times more and adapted into hyphae, while the gingival fibroblasts recorded a significantly (P<0.01 slow growth rate but a significantly higher level of IL-1β when in contact with CSC-pretreated C. albicans. CSC was thus able to modulate both C. albicans transition through the cell wall chitin content and the interaction between C. albicans and normal human gingival fibroblasts. These findings may be relevant to fungal infections in the oral cavity in smokers.

  15. Antioxidant status and selected biochemical parameters of porcine ovarian granulosa cells exposed to lead in vitro.

    Science.gov (United States)

    Capcarová, Marcela; Kolesárová, Adriana; Lukác, Norbert; Sirotkin, Alexander; Roychoudhury, Shubhadeep

    2009-12-01

    The objective of this study was to determine the activity of superoxide dismutase (SOD), total antioxidant status (TAS) and release of calcium, phosphorus, magnesium, sodium, potassium, total lipids, totals proteins, glucose, cholesterol and triglycerides by porcine ovarian granulosa cells cultured in vitro after lead acetate administration. The parameters were analyzed using semi-automated clinical chemistry analyzer Microlab 300, microprocessor-controlled analyzer EasyLite and spectrophotometer Genesys 10. Cells were cultured with lead acetate trihydrate [Pb(CH(3)COO)(2).3H(2)O] as follows: group Max (5 mg Pb(CH(3)COO)(2).3H(2)O/10 mL), group A (2.5 mg/10 mL), group B (0.83 mg/10 mL), group C (0.625 mg/10 mL), group D (0.455 mg/10 mL) and the control group without lead exposure for 18 hrs. The highest TAS was estimated in the control group without lead treatment in comparison with other groups (MAX, A, B, C, D). Statistical analyses showed significantly lower value (P 0.05) were detected in concentration of other studied parameters among observed groups, too.

  16. Caffeic Acid Reduces the Viability and Migration Rate of Oral Carcinoma Cells (SCC-25 Exposed to Low Concentrations of Ethanol

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    Arkadiusz Dziedzic

    2014-10-01

    Full Text Available Alcohol increases the risk of carcinoma originated from oral epithelium, but the biological effects of ultra-low doses of ethanol on existing carcinoma cells in combination with natural substances are still unclear. A role for ethanol (EtOH, taken in small amounts as an ingredient of some beverages or mouthwashes to change the growth behavior of established squamous cell carcinoma, has still not been examined sufficiently. We designed an in vitro study to determine the effect of caffeic acid (CFA on viability and migration ability of malignant oral epithelial keratinocytes, exposed to ultra-low concentrations (maximum 100 mmol/L EtOH. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-dimethyltetrazolium bromide and LDH (lactate dehydrogenase assays were used to assess the cytotoxic effect of EtOH/CFA and the viability of squamous carcinoma SCC-25 cells (ATCC CRL-1628, mobile part of the tongue. Tested EtOH concentrations were: 2.5, 5, 10, 25, 50, and 100 mmol/L, along with an equal CFA concentration of 50 μmol/L. Carcinoma cells’ migration was investigated by monolayer “wound” healing assay. We demonstrated that very low concentrations of EtOH ranging between 2.5 and 10 mmol/L may induce the viability of oral squamous cell carcinoma cells, while the results following addition of CFA reveal an antagonistic effect, attenuating pro-proliferative EtOH activity. The migration rate of oral squamous carcinoma cells can be significantly inhibited by the biological activity of caffeic acid.

  17. Quantification of epithelial cell differentiation in mammary glands and carcinomas from DMBA- and MNU-exposed rats.

    Directory of Open Access Journals (Sweden)

    Deepak Sharma

    Full Text Available Rat mammary carcinogenesis models have been used extensively to study breast cancer initiation, progression, prevention, and intervention. Nevertheless, quantitative molecular data on epithelial cell differentiation in mammary glands of untreated and carcinogen-exposed rats is limited. Here, we describe the characterization of rat mammary epithelial cells (RMECs by multicolor flow cytometry using antibodies against cell surface proteins CD24, CD29, CD31, CD45, CD49f, CD61, Peanut Lectin, and Thy-1, intracellular proteins CK14, CK19, and FAK, along with phalloidin and Hoechst staining. We identified the luminal and basal/myoepithelial populations and actively dividing RMECs. In inbred rats susceptible to mammary carcinoma development, we quantified the changes in differentiation of the RMEC populations at 1, 2, and 4 weeks after exposure to mammary carcinogens DMBA and MNU. DMBA exposure did not alter the percentage of basal or luminal cells, but upregulated CD49f (Integrin α6 expression and increased cell cycle activity. MNU exposure resulted in a temporary disruption of the luminal/basal ratio and no CD49f upregulation. When comparing DMBA- or MNU-induced mammary carcinomas, the RMEC differentiation profiles are indistinguishable. The carcinomas compared with mammary glands from untreated rats, showed upregulation of CD29 (Integrin β1 and CD49f expression, increased FAK (focal adhesion kinase activation especially in the CD29hi population, and decreased CD61 (Integrin β3 expression. This study provides quantitative insight into the protein expression phenotypes underlying RMEC differentiation. The results highlight distinct RMEC differentiation etiologies of DMBA and MNU exposure, while the resulting carcinomas have similar RMEC differentiation profiles. The methodology and data will enhance rat mammary carcinogenesis models in the study of the role of epithelial cell differentiation in breast cancer.

  18. The molecular signature of therapeutic mesenchymal stem cells exposes the architecture of the hematopoietic stem cell niche synapse

    Directory of Open Access Journals (Sweden)

    Mancardi Gianluigi

    2007-03-01

    Full Text Available Abstract Background The hematopoietic stem cells (HSCs niche of the bone marrow is comprised of HSCs, osteoblasts, endothelial cells and a stromal component of non-hematopoietic multipotent cells of mesenchymal origin named "mesenchymal stem cells" (MSCs. Results Here we studied the global transcriptional profile of murine MSCs with immuno-therapeutic potential and compared it with that of 486 publicly available microarray datasets from 12 other mouse tissues or cell types. Principal component analysis and hierarchical clustering identified a unique pattern of gene expression capable of distinctively classifying MSCs from other tissues and cells. We then performed an analysis aimed to identify absolute and relative abundance of transcripts in all cell types. We found that the set of transcripts uniquely expressed by MSCs is enriched in transcription factors and components of the Wnt signaling pathway. The analysis of differentially expressed genes also identified a set of genes specifically involved in the HSC niche and is complemented by functional studies that confirm the findings. Interestingly, some of these genes play a role in the maintenance of HSCs in a quiescent state supporting their survival and preventing them from proliferating and differentiating. We also show that MSCs modulate T cell functions in vitro and, upon in vivo administration, ameliorate experimental autoimmune encephalomyelitis (EAE. Conclusion Altogether, these findings provide novel and important insights on the mechanisms of T cell function regulation by MSCs and help to cement the rationale for their application in the treatment of autoimmune diseases.

  19. Autophagy counteracts apoptosis in human multiple myeloma cells exposed to oridonin in vitro via regulating intracellular ROS and SIRT1

    Institute of Scientific and Technical Information of China (English)

    Rong ZENG; Yan CHEN; Shuai ZHAO; Guo-hui CUI

    2012-01-01

    To explore the mechanisms underlying the oridonin-induced apoptosis and autophagy in human multiple myeloma cells in vitro.Methods:Human multiple myeloma RPMI8266 cells were used.The cell viability was assessed using MTT assay.Morphological changes of apoptosis and autophagy were observed under transmission electron microscope.TUNEL and annexin V-FITC/PI dual staining assays were used to measure apoptosis.Autophagy was analyzed using Western blot analysis and immunofluorescence staining with a QDs605 nm-Anti-LC3 fluorescent probe.Intracellular ROS was estimated with flow cytometry using DCFH-DA fluorescent probe.Protein levels of active caspase 3,Beclin 1 and SIRT1 were determined with Western blot analysis.Results:Exposure to oridonin (1-64 μmol/L) inhibited the proliferation of RPMI8266 cells in a concentration-dependent manner with an IC50 value of 6.74 μmol/L.Exposure to oridonin (7 μmol/L) simultaneously induced caspase 3-mediated apoptosis and Beclin 1-dependent autophagy of RPMI8266 cells.Both the apoptosis and autophagy were time-dependent,and apoptosis was the main effector pathway of cell death.Exposure to oridonin (7 μmol/L) increased intracellular ROS and reduced SIRT1 nuclear protein in a time-dependent manner.The blockade of intracellular generation of ROS by NAC (5 mmol/L) abrogated apoptosis,autophagy and the decrease of SIRT1 in the cells exposed to oridonin (7 μmol/L).The inhibition of autophagy by 3-MA (5 mmol/L) sensitized the cells to oridonin-induced apoptosis,which was accompanied by increased intracellular ROS and decreased SlRT1.Conclusion:Oridonin simultaneously induces apoptosis and autophagy of human multiple myeloma RPMI8266 cells via regulation of intracellular ROS generation and SIRT1 nuclear protein.The cytotoxicity of oridonin is mainly mediated through the apoptotic pathway,whereas the autophagy protects the cells from apoptosis.

  20. Measurement of oxidative damage to DNA in nanomaterial exposed cells and animals

    DEFF Research Database (Denmark)

    Møller, Peter; Jensen, Ditte Marie; Christophersen, Daniel Vest;

    2015-01-01

    Increased levels of oxidatively damaged DNA have been documented in studies of metal, metal oxide, carbon-based and ceramic engineered nanomaterials (ENMs). In particular, 8-oxo-7,8-dihydroguanine-2'-deoxyguanosine (8-oxodG) is widely assessed as a DNA nucleobase oxidation product, measured...... of oxidatively damaged DNA in lung tissue. Oral exposure to nanosized carbon black, TiO2 , carbon nanotubes and ZnO is associated with elevated levels of oxidatively damaged DNA in tissues. These observations are supported by cell culture studies showing concentration-dependent associations between ENM exposure...... between airway exposure to ENMs and oxidized DNA in lung tissue than studies showing acceptable baseline levels (odds ratio = 12.1, 95% confidence interval: 1.2-124). Nevertheless, reliable studies indicate that intratracheal instillation of nanosized carbon black is associated with increased levels...

  1. No DNA damage response and negligible genome-wide transcriptional changes in human embryonic stem cells exposed to terahertz radiation.

    Science.gov (United States)

    Bogomazova, A N; Vassina, E M; Goryachkovskaya, T N; Popik, V M; Sokolov, A S; Kolchanov, N A; Lagarkova, M A; Kiselev, S L; Peltek, S E

    2015-01-13

    Terahertz (THz) radiation was proposed recently for use in various applications, including medical imaging and security scanners. However, there are concerns regarding the possible biological effects of non-ionising electromagnetic radiation in the THz range on cells. Human embryonic stem cells (hESCs) are extremely sensitive to environmental stimuli, and we therefore utilised this cell model to investigate the non-thermal effects of THz irradiation. We studied DNA damage and transcriptome responses in hESCs exposed to narrow-band THz radiation (2.3 THz) under strict temperature control. The transcription of approximately 1% of genes was subtly increased following THz irradiation. Functional annotation enrichment analysis of differentially expressed genes revealed 15 functional classes, which were mostly related to mitochondria. Terahertz irradiation did not induce the formation of γH2AX foci or structural chromosomal aberrations in hESCs. We did not observe any effect on the mitotic index or morphology of the hESCs following THz exposure.

  2. Cytotoxicity, oxidative stress, and genotoxicity in human hepatocyte and embryonic kidney cells exposed to ZnO nanoparticles

    Science.gov (United States)

    Guan, Rongfa; Kang, Tianshu; Lu, Fei; Zhang, Zhiguo; Shen, Haitao; Liu, Mingqi

    2012-10-01

    Traces of zinc oxide nanoparticles (ZnO NPs) used may be found in the liver and kidney. The aim of this study is to determine the optimal viability assay for using with ZnO NPs and to assess their toxicity to human hepatocyte (L02) and human embryonic kidney (HEK293) cells. Cellular morphology, mitochondrial function (MTT assay), and oxidative stress markers (malondialdehyde, glutathione (GSH) and superoxide dismutase (SOD)) were assessed under control and exposed to ZnO NPs conditions for 24 h. The results demonstrated that ZnO NPs lead to cellular morphological modifications, mitochondrial dysfunction, and cause reduction of SOD, depletion of GSH, and oxidative DNA damage. The exact mechanism behind ZnO NPs toxicity suggested that oxidative stress and lipid peroxidation played an important role in ZnO NPs-elicited cell membrane disruption, DNA damage, and subsequent cell death. Our preliminary data suggested that oxidative stress might contribute to ZnO NPs cytotoxicity.

  3. Comparison of autosomal mutations in mouse kidney epithelial cells exposed to iron ions in situ or in culture.

    Science.gov (United States)

    Turker, Mitchell S; Connolly, Lanelle; Dan, Cristian; Lasarev, Michael; Gauny, Stacey; Kwoh, Ely; Kronenberg, Amy

    2009-11-01

    Exposure to accelerated iron ions represents a significant health risk in the deep space environment because it induces mutations that can cause cancer. A mutation assay was used to determine the full spectrum of autosomal mutations induced by exposure to 2 Gy of 1 GeV/nucleon iron ions in intact kidney epithelium, and the results were compared with mutations induced in cells of a kidney epithelial cell line exposed in vitro. A molecular analysis for loss of heterozygosity (LOH) for polymorphic loci on chromosome 8, which harbors Aprt, demonstrated iron-ion induction of mitotic recombination, interstitial deletion, and discontinuous LOH events. Iron-ion-induced deletions were detected more readily with the in vitro assay, whereas discontinuous LOH was detected more readily in the intact kidney. The specific induction of discontinuous LOH in vivo suggests that this mutation pattern may serve as an indicator of genomic instability. Interestingly, the frequency of small intragenic events increased as a function of time after exposure, suggesting non-targeted effects. In total, the results demonstrate that 1 GeV/nucleon iron ions can elicit a variety of autosomal mutations and that the cellular microenvironment and the sampling time after exposure can influence the distribution of these mutations in epithelial cell populations.

  4. Genomic Profiling of a Human Leukemic Monocytic Cell-Line (THP-1 Exposed to Alpha Particle Radiation

    Directory of Open Access Journals (Sweden)

    Vinita Chauhan

    2012-01-01

    Full Text Available This study examined alpha (α- particle radiation effects on global changes in gene expression in human leukemic monocytic cells (THP-1 for the purposes of mining for candidate biomarkers that could be used for the development of a biological assessment tool. THP-1 cells were exposed to α-particle radiation at a dose range of 0 to 1.5 Gy. Twenty-four hours and three days after exposure gene expression was monitored using microarray technology. A total of 16 genes were dose responsive and classified as early onset due to their expression 24 h after exposure. Forty-eight transcripts were dose responsive and classified as late-onset as they were expressed 72 h after exposure. Among these genes, 6 genes were time and dose responsive and validated further using alternate technology. These transcripts were upregulated and associated with biological processes related to immune function, organelle stability and cell signalling/communication. This panel of genes merits further validation to determine if they are strong candidate biomarkers indicative of α-particle exposure.

  5. DNA damage in human germ cell exposed to the some food additives in vitro.

    Science.gov (United States)

    Pandir, Dilek

    2016-08-01

    The use of food additives has increased enormously in modern food technology but they have adverse effects in human healthy. The aim of this study was to investigate the DNA damage of some food additives such as citric acid (CA), benzoic acid (BA), brilliant blue (BB) and sunset yellow (SY) which were investigated in human male germ cells using comet assay. The sperm cells were incubated with different concentrations of these food additives (50, 100, 200 and 500 μg/mL) for 1 h at 32 °C. The results showed for CA, BA, BB and SY a dose dependent increase in tail DNA%, tail length and tail moment in human sperm when compared to control group. When control values were compared in the studied parameters in the treatment concentrations, SY was found to exhibit the highest level of DNA damage followed by BB > BA > CA. However, none of the food additives affected the tail DNA%, tail length and tail moment at 50 and 100 μg/mL. At 200 μg/mL of SY, the tail DNA% and tail length of sperm were 95.80 ± 0.28 and 42.56 ± 4.66, for BB the values were 95.06 ± 2.30 and 39.56 ± 3.78, whereas for BA the values were 89.05 ± 2.78 and 31.50 ± 0.71, for CA the values were 88.59 ± 6.45 and 13.59 ± 2.74, respectively. However, only the highest concentration of the used food additives significantly affected the studied parameters of sperm DNA. The present results indicate that SY and BB are more harmful than BA and CA to human sperm in vitro.

  6. Sodium nitrite induces acute central nervous system toxicity in guinea pigs exposed to systemic cell-free hemoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Buehler, Paul W.; Butt, Omer I. [Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD (United States); D' Agnillo, Felice, E-mail: felice.dagnillo@fda.hhs.gov [Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD (United States)

    2011-06-10

    Highlights: {yields} Toxicological implications associated with the use of NaNO{sub 2} therapy to treat systemic cell-free Hb exposure are not well-defined. {yields} Systemic Hb exposure followed by NaNO{sub 2} infusion induces acute CNS toxicities in guinea pigs. {yields} These CNS effects were not reproduced by the infusion of cell-free Hb or NaNO{sub 2} alone. {yields} NaNO{sub 2}-mediated oxidation of cell-free Hb may play a causative role in the observed CNS changes. -- Abstract: Systemic cell-free hemoglobin (Hb) released via hemolysis disrupts vascular homeostasis, in part, through the scavenging of nitric oxide (NO). Sodium nitrite (NaNO{sub 2}) therapy can attenuate the hypertensive effects of Hb. However, the chemical reactivity of NaNO{sub 2} with Hb may enhance heme- or iron-mediated toxicities. Here, we investigate the effect of NaNO{sub 2} on the central nervous system (CNS) in guinea pigs exposed to systemic cell-free Hb. Intravascular infusion of NaNO{sub 2}, at doses sufficient to alleviate Hb-mediated blood pressure changes, reduced the expression of occludin, but not zona occludens-1 (ZO-1) or claudin-5, in cerebral tight junctions 4 h after Hb infusion. This was accompanied by increased perivascular heme oxygenase-1 expression, neuronal iron deposition, increased astrocyte and microglial activation, and reduced expression of neuron-specific nuclear protein (NeuN). These CNS changes were not observed in animals treated with Hb or NaNO{sub 2} alone. Taken together, these findings suggest that the use of nitrite salts to treat systemic Hb exposure may promote acute CNS toxicity.

  7. Gene expression changes in primary human nasal epithelial cells exposed to formaldehyde in vitro.

    Science.gov (United States)

    Neuss, Simone; Holzmann, Karlheinz; Speit, Günter

    2010-10-05

    Using various exposure conditions, we studied the induction of DNA-protein crosslinks (DPX) by formaldehyde (FA) and their removal in primary human nasal epithelial cells (HNEC). DPX were indirectly measured by the alkaline comet assay as the reduction of gamma ray-induced DNA migration. DPX are the most relevant primary DNA alterations induced by FA and the comet assay is a very sensitive method for the detection of FA-induced DPX. In parallel experiments, we investigated changes in gene expression by using a full-genome human microarray. After a single treatment with FA (50-200muM), concentration- and time-dependent changes in gene expression were seen under conditions that also induced genotoxicity. Repeated treatments with low FA concentrations (20 and 50muM) did not lead to a significant induction of DPX but repeated treatments with 50muM FA changed the expression of more than 100 genes. Interestingly, altered expression of genes involved in the main pathways for FA detoxification and the repair of DPX were not specifically detected.

  8. Proteomic analysis of blood cells in fish exposed to chemotherapeutics: evidence for long term effects.

    Science.gov (United States)

    Pierrard, Marie-Aline; Kestemont, Patrick; Phuong, Nguyen Thanh; Tran, Minh Phu; Delaive, Edouard; Thezenas, Marie-Laëtitia; Dieu, Marc; Raes, Martine; Silvestre, Frédéric

    2012-04-18

    Proteomics technology are increasingly used in ecotoxicological studies to characterize and monitor biomarkers of exposure. The present study aims at identifying long term effects of malachite green (MG) exposure on the proteome of peripheral blood mononuclear cells (PBMC) from the Asian catfish, Pangasianodon hypophthalmus. A common (0.1 ppm) concentration for therapeutic treatment was applied twice with a 72 h interval. PBMC were collected directly at the end of the second bath of MG (T1) and after 1 month of decontamination (T2). Analytical 2D-DIGE gels were run and a total of 2551±364 spots were matched. Among them, MG induced significant changes in abundance of 116 spots with no recovery after one month of decontamination. Using LC-MS/MS and considering single identification per spot, we could identify 25 different proteins. Additionally, MG residues were measured in muscle and in blood indicating that leuco-MG has almost totally disappeared after one month of decontamination. This work highlights long term effects of MG treatment on the PBMC proteome from fish intended for human consumption.

  9. The mechanisms of insulin secretion and calcium signaling in pancreatic β-cells exposed to fluoroquinolones.

    Science.gov (United States)

    Bito, Motoki; Tomita, Takashi; Komori, Mika; Taogoshi, Takanori; Kimura, Yasuhiro; Kihira, Kenji

    2013-01-01

    Fluoroquinolones reportedly induce hypoglycemia through stimulation of insulin secretion from pancreatic β-cells via inhibition of K(ATP) channels and activation of L-type voltage-dependent Ca(2+) channels. In physiological condition, the cytosolic Ca(2+) concentration ([Ca(2+)](c)) is also regulated by release of Ca(2+) from intracellular Ca(2+) stores. In this study, we investigated the mechanism of insulin secretion induced by fluoroquinolones, with respect to intracellular Ca(2+) stores. Even where the absence of supplemental extracellular Ca(2+), insulin secretion and [Ca(2+)](c) were increased by gatifloxacin, levofloxacin or tolbutamide. Insulin secretion and the rise of [Ca(2+)](c) induced by fluoroquinolones were reduced by depleting of Ca(2+) in endoplasmic reticumum (ER) by thapsigargin, and inhibiting ryanodine receptor of ER by dantrolene. Inhibition of inositol 1,4,5-triphosphate receptor of ER by xestospongin C suppressed insulin secretion induced by fluoroquinolones, whereas it did not affect [Ca(2+)](c). Destruction of acidic Ca(2+) stores such as lysosome and lysosome-related organelles by glycyl-L-phenylalanine-2-nephthylamide (GPN) did not affect insulin secretion and the rise of [Ca(2+)](c) induced by fluoroquinolones. The increase in insulin and [Ca(2+)](c) induced by tolbutamide were reduced by thapsigargin, dantrolene, and GPN but not by xestospongin C. In conclusion, fluoroquinolones induces Ca(2+) release from ER mediated by the ryanodine receptor, and the reaction might involve in insulin secretion. Sulfonylureas induce Ca(2+) release from GPN-sensitive acidic Ca(2+) stores, but fluoroquinolones did not.

  10. Nrf2-dependent repression of interleukin-12 expression in human dendritic cells exposed to inorganic arsenic.

    Science.gov (United States)

    Macoch, Mélinda; Morzadec, Claudie; Génard, Romain; Pallardy, Marc; Kerdine-Römer, Saadia; Fardel, Olivier; Vernhet, Laurent

    2015-11-01

    Inorganic arsenic, a well-known Nrf2 inducer, exerts immunosuppressive properties. In this context, we recently reported that the differentiation of human blood monocytes into immature dendritic cells (DCs), in the presence of low and noncytotoxic concentrations of arsenic, represses the ability of DCs to release key cytokines in response to different stimulating agents. Particularly, arsenic inhibits the expression of human interleukin-12 (IL-12, also named IL-12p70), a major proinflammatory cytokine that controls the differentiation of Th1 lymphocytes. In the present study, we determined if Nrf2 could contribute to these arsenic immunotoxic effects. To this goal, human monocyte-derived DCs were first differentiated in the absence of metalloid and then pretreated with arsenic just before DC stimulation with lipopolysaccharide (LPS). Under these experimental conditions, arsenic rapidly and stably activates Nrf2 and increases the expression of Nrf2 target genes. It also significantly inhibits IL-12 expression in activated DCs, at both mRNA and protein levels. Particularly, arsenic reduces mRNA levels of IL12A and IL12B genes which encodes the p35 and p40 subunits of IL-12p70, respectively. tert-Butylhydroquinone (tBHQ), a reference Nrf2 inducer, mimics arsenic effects and potently inhibits IL-12 expression. Genetic inhibition of Nrf2 expression markedly prevents the repression of both IL12 mRNA and IL-12 protein levels triggered by arsenic and tBHQ in human LPS-stimulated DCs. In addition, arsenic significantly reduces IL-12 mRNA levels in LPS-activated bone marrow-derived DCs from Nrf2+/+ mice but not in DCs from Nrf2-/- mice. Finally, we show that, besides IL-12, arsenic significantly reduces the expression of IL-23, another heterodimer containing the p40 subunit. In conclusion, our study demonstrated that arsenic represses IL-12 expression in human-activated DCs by specifically stimulating Nrf2 activity.

  11. Investigation of toxic factors affecting cells of rat brains exposed to 3-methylcatechol

    Directory of Open Access Journals (Sweden)

    George Emílio Sampaio Barreto

    2007-09-01

    Full Text Available The aim of this work was to study the effects of 3MC on the peroxidation of biomolecules in nuclear fractions and nonsynaptic mitochondrial respiration in organelles obtained from rat brains. The cytotoxicity towards rat primary astrocytes in vitro was also tested. 3MC at 1mM oxidized consuming oxygen at a rate of 1.98 ± 0.19 µM.min-1 and formed reactive quinones. At the same concentration, 3MC induced peroxidation of biomolecules in nuclear fractions obtained from rat brain homogenates and inhibited state 2 FADH2-linked respiration in nonsynaptic mitochondria. Furthermore, 3MC oxidized in the culture medium, leading to the formation of quinones. This toluene metabolite was cytotoxic to rat primary astrocytes. The concentration that killed 50% of cells after 72 h was 107 mM. The results of the study indicated a direct relationship between cytotoxicity and 3MC oxidation.O 3-metilcatecol (3MC é um metabólito do tolueno. Para esclarecer se o 3MC seria tóxico para o sistema nervoso central, examinou-se seus efeitos sobre a peroxidação de biomoléculas em frações nucleares e a respiração mitocondrial em organelas obtidas de cérebros de ratos. Também se testou a citotoxicidade para astrócitos primários de ratos. O 3MC a 1mM oxida-se consumindo oxigênio a uma taxa de 1,98 ± 0,19 mM.min-1, formando quinonas reativas. Nessa mesma concentração o 3MC peroxidou biomoléculas nas frações nucleares. Esse composto também inibiu o estado 2 da respiração mitocondrial associada ao FADH2. Além disso, o 3MC também se oxida em meio de cultura levando à formação de quinonas. Esse metabólito do tolueno foi citotóxico para astrócitos de ratos. A concentração que matou 50% das células após 72 horas foi 107 mM. Os resultados desse estudo indicam uma relação direta entre a citotoxicidade e a oxidação do 3MC.

  12. A homologue of the defender against the apoptotic death gene (dad1) in UV-exposed Chlamydomonas cells is downregulated with the onset of programmed cell death

    Indian Academy of Sciences (India)

    Swati Moharikar; Jacinta S D’souza; Basuthkar J Rao

    2007-03-01

    We report here the isolation of a homologue of the potential anti-apoptotic gene, defender against apoptotic death (dad1) from Chlamydomonas reinhardtii cells. Using polymerase chain reaction (PCR), we investigated its expression in the execution process of programmed cell death (PCD) in UV-C exposed dying C. reinhardtii cells. Reverse-transcriptase (RT)-PCR showed that C. reinhardtii dad1 amplification was drastically reduced in UV-C exposed dying C. reinhardtii cells. We connect the downregulation of dad1 with the upregulation of apoptosis protease activating factor-1 (APAF-1) and the physiological changes that occur in C. reinhardtii cells upon exposure to 12 J/m2 UV-C in order to show a reciprocal relationship between proapoptotic and inhibitor of apoptosis factors. The temporal changes indicate a correlation between the onset of cell death and dad1 downregulation. The sequence of the PCR product of the cDNA encoding the dad1 homologue was aligned with the annotated dad1 (C_20215) from the Chlamydomonas database (http://genome.jgi-psf.org:8080/annotator/servlet/jgi.annotation.Annotation?pDb=chlre2); Annotation?pDb=chlre2); this sequence was found to show 100% identity, both at the nucleotide and amino acid level. The 327 bp transcript showed an open reading frame of 87 amino acid residues. The deduced amino acid sequence of the putative C. reinhardtii DAD1 homologue showed 54% identity with Oryza sativa, 56% identity with Drosophila melanogaster, 66% identity with Xenopus laevis, and 64% identity with Homo sapiens, Sus scrofa, Gallus gallus, Rattus norvegicus and Mus musculus.

  13. Exposing diversity

    DEFF Research Database (Denmark)

    Nørtoft, Kamilla; Nordentoft, Helle Merete

    . A prominent research theme in health care studies is, therefore, to explicate the gap between theory and practice. The question this paper addresses is how a learning environment can be designed to bridge this theory-practice gap, expose the differences in situated interactions and qualify health...... in the homes of older people and in pedagogical institutions targeting older people. In the paper we look at the potentials and challenges in working with ethnographic video narratives as a pedagogical tool. Our findings indicate that the use of video narratives has the potential to expose the diversity...

  14. Live-Cell Imaging Visualizes Frequent Mitotic Skipping During Senescence-Like Growth Arrest in Mammary Carcinoma Cells Exposed to Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Masatoshi, E-mail: msuzuki@nagasaki-u.ac.jp [Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki (Japan); Yamauchi, Motohiro; Oka, Yasuyoshi; Suzuki, Keiji; Yamashita, Shunichi [Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki (Japan)

    2012-06-01

    Purpose: Senescence-like growth arrest in human solid carcinomas is now recognized as the major outcome of radiotherapy. This study was designed to analyze cell cycle during the process of senescence-like growth arrest in mammary carcinoma cells exposed to X-rays. Methods and Materials: Fluorescent ubiquitination-based cell cycle indicators were introduced into the human mammary carcinoma cell line MCF-7. Cell cycle was sequentially monitored by live-cell imaging for up to 5 days after exposure to 10 Gy of X-rays. Results: Live-cell imaging revealed that cell cycle transition from G2 to G1 phase without mitosis, so-called mitotic skipping, was observed in 17.1% and 69.8% of G1- and G2-irradiated cells, respectively. Entry to G1 phase was confirmed by the nuclear accumulation of mKO{sub 2}-hCdt1 as well as cyclin E, which was inversely correlated to the accumulation of G2-specific markers such as mAG-hGeminin and CENP-F. More than 90% of cells skipping mitosis were persistently arrested in G1 phase and showed positive staining for the senescent biochemical marker, which is senescence-associated ss-galactosidase, indicating induction of senescence-like growth arrest accompanied by mitotic skipping. While G2 irradiation with higher doses of X-rays induced mitotic skipping in approximately 80% of cells, transduction of short hairpin RNA (shRNA) for p53 significantly suppressed mitotic skipping, suggesting that ionizing radiation-induced mitotic skipping is associated with p53 function. Conclusions: The present study found the pathway of senescence-like growth arrest in G1 phase without mitotic entry following G2-irradiation.

  15. Sodium nitrite induces acute central nervous system toxicity in guinea pigs exposed to systemic cell-free hemoglobin.

    Science.gov (United States)

    Buehler, Paul W; Butt, Omer I; D'Agnillo, Felice

    2011-06-10

    Systemic cell-free hemoglobin (Hb) released via hemolysis disrupts vascular homeostasis, in part, through the scavenging of nitric oxide (NO). Sodium nitrite (NaNO(2)) therapy can attenuate the hypertensive effects of Hb. However, the chemical reactivity of NaNO(2) with Hb may enhance heme- or iron-mediated toxicities. Here, we investigate the effect of NaNO(2) on the central nervous system (CNS) in guinea pigs exposed to systemic cell-free Hb. Intravascular infusion of NaNO(2), at doses sufficient to alleviate Hb-mediated blood pressure changes, reduced the expression of occludin, but not zona occludens-1 (ZO-1) or claudin-5, in cerebral tight junctions 4h after Hb infusion. This was accompanied by increased perivascular heme oxygenase-1 expression, neuronal iron deposition, increased astrocyte and microglial activation, and reduced expression of neuron-specific nuclear protein (NeuN). These CNS changes were not observed in animals treated with Hb or NaNO(2) alone. Taken together, these findings suggest that the use of nitrite salts to treat systemic Hb exposure may promote acute CNS toxicity.

  16. Comprehensive analysis of 5-aminolevulinic acid dehydrogenase (ALAD variants and renal cell carcinoma risk among individuals exposed to lead.

    Directory of Open Access Journals (Sweden)

    Dana M van Bemmel

    Full Text Available BACKGROUND: Epidemiologic studies are reporting associations between lead exposure and human cancers. A polymorphism in the 5-aminolevulinic acid dehydratase (ALAD gene affects lead toxicokinetics and may modify the adverse effects of lead. METHODS: The objective of this study was to evaluate single-nucleotide polymorphisms (SNPs tagging the ALAD region among renal cancer cases and controls to determine whether genetic variation alters the relationship between lead and renal cancer. Occupational exposure to lead and risk of cancer was examined in a case-control study of renal cell carcinoma (RCC. Comprehensive analysis of variation across the ALAD gene was assessed using a tagging SNP approach among 987 cases and 1298 controls. Occupational lead exposure was estimated using questionnaire-based exposure assessment and expert review. Odds ratios (OR and 95% confidence intervals (CI were calculated using logistic regression. RESULTS: The adjusted risk associated with the ALAD variant rs8177796(CT/TT was increased (OR = 1.35, 95%CI = 1.05-1.73, p-value = 0.02 when compared to the major allele, regardless of lead exposure. Joint effects of lead and ALAD rs2761016 suggest an increased RCC risk for the homozygous wild-type and heterozygous alleles ((GGOR = 2.68, 95%CI = 1.17-6.12, p = 0.01; (GAOR = 1.79, 95%CI = 1.06-3.04 with an interaction approaching significance (p(int = 0.06. No significant modification in RCC risk was observed for the functional variant rs1800435(K68N. Haplotype analysis identified a region associated with risk supporting tagging SNP results. CONCLUSION: A common genetic variation in ALAD may alter the risk of RCC overall, and among individuals occupationally exposed to lead. Further work in larger exposed populations is warranted to determine if ALAD modifies RCC risk associated with lead exposure.

  17. Effects of nitrogen on the apoptosis of and changes in gene expression in human lymphoma U937 cells exposed to argon-based cold atmospheric pressure plasma.

    Science.gov (United States)

    Tabuchi, Yoshiaki; Uchiyama, Hidefumi; Zhao, Qing-Li; Yunoki, Tatsuya; Andocs, Gabor; Nojima, Nobuyuki; Takeda, Keigo; Ishikawa, Kenji; Hori, Masaru; Kondo, Takashi

    2016-06-01

    Cold atmospheric pressure plasma (CAP) is known as a source of biologically active agents, such as reactive oxygen species (ROS) and reactive nitrogen species (RNS). In the present study, we examined the effects of nitrogen (N2) on the apoptosis of and changes in gene expression in human lymphoma U937 cells exposed to argon (Ar)-CAP. Enormous amounts of hydroxyl (·OH) radicals in aqueous solution were produced using Ar‑CAP generated using a 20 kHz low frequency at 18 kV with a flow rate of 2 l/min. The increase in the levels of ·OH radicals was significantly attenuated by the addition of N2 to Ar gas. On the other hand, the level of total nitrate/nitrite in the supernatant was significantly elevated in the Ar + N2-CAP‑exposed U937 cells. When the cells were exposed to Ar‑CAP, a significant increase in apoptosis was observed, whereas apoptosis was markedly decreased in the cells exposed to Ar + N2-CAP. Microarray and pathway analyses revealed that a newly identified gene network containing a number of heat shock proteins (HSPs), anti-apoptotic genes, was mainly associated with the biological function of the prevention of apoptosis. Quantitative PCR revealed that the expression levels of HSPs were significantly elevated in the cells exposed to Ar + N2-CAP than those exposed to Ar‑CAP. These results indicate that N2 gas in Ar‑CAP modifies the ratio of ROS to RNS, and suppresses the apoptosis induced by Ar‑CAP. The modulation of gaseous conditions in CAP may thus prove to be useful for future clinical applications, such as for switching from a sterilizing mode to cytocidal effect for cancer cells.

  18. Immunohistochemical analysis of cytochrome P4501A induction in organs and cell types of Rivulus marmoratus exposed to waterborne 2,3,7,8-tetrachlorodibenzo-p-dioxin

    Energy Technology Data Exchange (ETDEWEB)

    Stegeman, J.; Smolowitz, R.; Burnett, K.; DiBona, D. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States)]|[Medical College of South Carolina, Charleston, SC (United States)

    1994-12-31

    Identifying target cells and organs is critical to establishing the sites and mechanisms of toxicity of Ah-receptor agonists. Previous studies have described the localization of CYPLA induced in multiple organs of fish exposed to Ah-receptor agonists. Here the authors compare the responses in multiple cell types and organs of small fish (Rivulus) exposed to waterborne TCDD. Adult fish were exposed to TCDD at concentrations from 0.01 to 10 ng/liter for 48 hours, then prepared and analyzed by immunohistochemistry with monoclonal antibody to teleost CYPIAI. At the highest dose profound induction was detected in virtually every organ. Structures staining intensely were: nasal and cephalic chemoreceptors, including sensory and basal cells; superficial cells in skin and pharynx; cartilage cells (chondrocytes) in the head, gills, growth plates and fins; epithelial and endothelial cells of liver, gut, kidney, and gill; pseudobranch vessels and glandular cells; eye lens epithelium; endothelium in vessels of eye, brain, skin, muscle, thymus and gonad. Lesser concentrations of TCDD elicited less strong responses, and control fish showed mild staining only in cartilage structures. The dose-dependent patterns of induction differed between different cell types. Responsive cells identified is these fish indicate sites where toxicity associated with Ah-receptor agonists or with CYPLA function may be expressed.

  19. Basal Cell Carcinoma on the Pubic Area: Report of a Case and Review of 19 Korean Cases of BCC from Non-sun-exposed Areas.

    Science.gov (United States)

    Park, Jin; Cho, Yong-Sun; Song, Ki-Hun; Lee, Jong-Sun; Yun, Seok-Kweon; Kim, Han-Uk

    2011-08-01

    Basal cell carcinoma (BCC) is one of the most commonly diagnosed malignant skin tumors and develops characteristically on sun-exposed areas, such as the head and neck. Ultraviolet light exposure is an important etiologic factor in BCCs, and BCCs arising from non-sun- exposed areas are, therefore, very rare. In particular, the axilla, nipple, the genital and perianal areas are not likely to be exposed to ultraviolet light; thus, if BCC develops in these areas, other predisposing factors should be considered. Herein, we report a case of BCC arising on the pubic area in a 70-year-old man. We also performed a survey of the literature and discussed the 19 cases of BCC from non-sun-exposed areas reported to date in Korea.

  20. Biomarker analysis of liver cells exposed to surfactant-wrapped and oxidized multi-walled carbon nanotubes (MWCNTs)

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, W. Matthew, E-mail: Henderson.Matt@epa.gov [U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, 960 College Station Road, Athens 30605, GA (United States); Bouchard, Dermont [U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, 960 College Station Road, Athens 30605, GA (United States); Chang, Xiaojun [Grantee to U.S. Environmental Protection Agency via National Research Council Cooperative Agreement, Athens 30605, GA (United States); Al-Abed, Souhail R. [U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, 26 Martin Luther King Dr. W, Cincinnati, OH 45268 (United States); Teng, Quincy [U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, 960 College Station Road, Athens 30605, GA (United States)

    2016-09-15

    Carbon nanotubes (CNTs) have great potential in industrial, consumer, and mechanical applications, based partly on their unique structural, optical and electronic properties. CNTs are commonly oxidized or treated with surfactants to facilitate aqueous solution processing, and these CNT surface modifications also increase possible human and ecological exposures to nanoparticle-contaminated waters. To determine the exposure outcomes of oxidized and surfactant-wrapped multiwalled carbon nanotubes (MWCNTs) on biochemical processes, metabolomics-based profiling of human liver cells (C3A) was utilized. Cells were exposed to 0, 10, or 100 ng/mL of MWCNTs for 24 and 48 h; MWCNT particle size distribution, charge, and aggregation were monitored concurrently during exposures. Following MWCNT exposure, cellular metabolites were extracted, lyophilized, and buffered for {sup 1}H NMR analysis. Acquired spectra were subjected to both multivariate and univariate analysis to determine the consequences of nanotube exposure on the metabolite profile of C3A cells. Resulting scores plots illustrated temporal and dose-dependent metabolite responses to all MWCNTs tested. Loadings plots coupled with t-test filtered spectra identified metabolites of interest. XPS analysis revealed the presence of hydroxyl and carboxyl functionalities on both MWCNTs surfaces. Metal content analysis by ICP-AES indicated that the total mass concentration of the potentially toxic impurities in the exposure experiments were extremely low (i.e. [Ni] ≤ 2 × 10{sup −10} g/mL). Preliminary data suggested that MWCNT exposure causes perturbations in biochemical processes involved in cellular oxidation as well as fluxes in amino acid metabolism and fatty acid synthesis. Dose-response trajectories were apparent and spectral peaks related to both dose and MWCNT dispersion methodologies were determined. Correlations of the significant changes in metabolites will help to identify potential biomarkers associated with

  1. Assessment of genotoxic and cytotoxic hazards in brain and bone marrow cells of newborn rats exposed to extremely low-frequency magnetic field.

    Science.gov (United States)

    Rageh, Monira M; El-Gebaly, Reem H; El-Bialy, Nihal S

    2012-01-01

    The present study aimed to evaluate the association between whole body exposure to extremely low frequency magnetic field (ELF-MF) and genotoxic , cytotoxic hazards in brain and bone marrow cells of newborn rats. Newborn rats (10 days after delivery) were exposed continuously to 50 Hz, 0.5 mT for 30 days. The control group was treated as the exposed one with the sole difference that the rats were not exposed to magnetic field. Comet assay was used to quantify the level of DNA damage in isolated brain cells. Also bone marrow cells were flushed out to assess micronucleus induction and mitotic index. Spectrophotometric methods were used to measure the level of malondialdehyde (MDA) and the activity of glutathione (GSH) and superoxide dismutase (SOD). The results showed a significant increase in the mean tail moment indicating DNA damage in exposed group (P < 0.01, 0.001, 0.0001). Moreover ELF-MF exposure induced a significant (P < 0.01, 0.001) four folds increase in the induction of micronucleus and about three folds increase in mitotic index (P < 0.0001). Additionally newborn rats exposed to ELF-MF showed significant higher levels of MDA and SOD (P < 0.05). Meanwhile ELF-MF failed to alter the activity of GSH. In conclusion, the present study suggests an association between DNA damage and ELF-MF exposure in newborn rats.

  2. Assessment of Genotoxic and Cytotoxic Hazards in Brain and Bone Marrow Cells of Newborn Rats Exposed to Extremely Low-Frequency Magnetic Field

    Directory of Open Access Journals (Sweden)

    Monira M. Rageh

    2012-01-01

    Full Text Available The present study aimed to evaluate the association between whole body exposure to extremely low frequency magnetic field (ELF-MF and genotoxic , cytotoxic hazards in brain and bone marrow cells of newborn rats. Newborn rats (10 days after delivery were exposed continuously to 50 Hz, 0.5 mT for 30 days. The control group was treated as the exposed one with the sole difference that the rats were not exposed to magnetic field. Comet assay was used to quantify the level of DNA damage in isolated brain cells. Also bone marrow cells were flushed out to assess micronucleus induction and mitotic index. Spectrophotometric methods were used to measure the level of malondialdehyde (MDA and the activity of glutathione (GSH and superoxide dismutase (SOD. The results showed a significant increase in the mean tail moment indicating DNA damage in exposed group (P<0.01,0.001,0.0001. Moreover ELF-MF exposure induced a significant (P<0.01,0.001 four folds increase in the induction of micronucleus and about three folds increase in mitotic index (P<0.0001. Additionally newborn rats exposed to ELF-MF showed significant higher levels of MDA and SOD (P<0.05. Meanwhile ELF-MF failed to alter the activity of GSH. In conclusion, the present study suggests an association between DNA damage and ELF-MF exposure in newborn rats.

  3. Antibody ligation of CM1 on cisplatin-exposed HeLa cells induces apoptosis through reactive oxygen species-dependent Fas ligand expression.

    Science.gov (United States)

    Park, Ga Bin; Kim, Daejin; Yoon, Hoi Soo; Kim, Yeong-Seok; Lee, Hyun-Kyung; Kim, Ki Tae; Jeong, Dae Hoon; Hur, Dae Young

    2014-06-01

    Centrocyte/centroblast marker 1 (CM1) has been identified as a pro-apoptosis molecule on B-cell lymphoma cells as well as several types of cancer cells. In this study, we investigated its signaling mechanism in HeLa cells after treatment with cisplatin in order to potentially identify a new therapeutic target. The CM1 molecule was induced on the surface of cisplatin-exposed HeLa cells. In these cells, ligation of CM1 with anti-CM1 monoclonal antibodies inhibited cell proliferation and produced reactive oxygen species. Fas ligand (FasL) expression was upregulated without upregulating Fas in cisplatin-exposed HeLa cells after CM1 stimulation. Pretreatment with N-acetylcysteine, a pan-capase inhibitor, and ZB4, an antagonistic anti-Fas antibody, effectively inhibited the apoptotic effect triggered by CM1. CM1 ligation induced apoptosis through disruption of the mitochondrial membrane potential, decreased Bcl-2 and phosphorylated ERK expression. These findings identify CM1 as a potential new therapeutic target related to cisplatin-exposed cervical cancer.

  4. In vitro response of the human breast cancer cell line MDAMB-231 and human peripheral blood mononuclear cells exposed to {sup 60}Co at single fraction

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Lidia Maria; Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear]. E-mail: lidia.andrade@unifenas.br; Leite, M.F. [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Fisiologia e Biofisica; Goes, A.M. [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia

    2005-10-15

    Radiotherapy using gamma rays is a common modality of breast cancer treatment. The aim of this research is to investigate the biological response of the human breast cancer cell line MDAMB-231 and human peripheral blood mononuclear cells (PBMC) exposed in vitro to {sup 60} Co irradiation at a single fraction of 10 Gy, 25 Gy and 50 Gy doses at 136,4 cGy.min{sup -1} rate. Cells were irradiated at room temperature by the Theratron 80 radiotherapy system. Biological response was evaluated through cellular viability using MTT assay and nucleus damages visualized by Propidium Iodide assay and electrophoresis agarose gel after gamma irradiation. Nucleus damages induced by {sup 60} Co irradiation were compared to damage caused by cell exposure to 10% methanol. The 50 Gy dose of irradiation did not stimulate nucleus damages at the same level as that affected by 10% methanol induction in the MDAMB-231. Further studies are necessary to understand these mechanisms in the MDAMB-231 human breast carcinoma cell line.(author)

  5. Activation of the adenylyl cyclase/cyclic AMP/protein kinase A pathway in endothelial cells exposed to cyclic strain

    Science.gov (United States)

    Cohen, C. R.; Mills, I.; Du, W.; Kamal, K.; Sumpio, B. E.

    1997-01-01

    The aim of this study was to assess the involvement of the adenylyl cyclase/cyclic AMP/protein kinase A pathway (AC) in endothelial cells (EC) exposed to different levels of mechanical strain. Bovine aortic EC were seeded to confluence on flexible membrane-bottom wells. The membranes were deformed with either 150 mm Hg (average 10% strain) or 37.5 mm Hg (average 6% strain) vacuum at 60 cycles per minute (0.5 s strain; 0.5 s relaxation) for 0-60 min. The results demonstrate that at 10% average strain (but not 6% average strain) there was a 1.5- to 2.2-fold increase in AC, cAMP, and PKA activity by 15 min when compared to unstretched controls. Further studies revealed an increase in cAMP response element binding protein in EC subjected to the 10% average strain (but not 6% average strain). These data support the hypothesis that cyclic strain activates the AC/cAMP/PKA signal transduction pathway in EC which may occur by exceeding a strain threshold and suggest that cyclic strain may stimulate the expression of genes containing cAMP-responsive promoter elements.

  6. Aerosol generation and characterization of multi-walled carbon nanotubes exposed to cells cultured at the air-liquid interface.

    Science.gov (United States)

    Polk, William W; Sharma, Monita; Sayes, Christie M; Hotchkiss, Jon A; Clippinger, Amy J

    2016-04-23

    Aerosol generation and characterization are critical components in the assessment of the inhalation hazards of engineered nanomaterials (NMs). An extensive review was conducted on aerosol generation and exposure apparatus as part of an international expert workshop convened to discuss the design of an in vitro testing strategy to assess pulmonary toxicity following exposure to aerosolized particles. More specifically, this workshop focused on the design of an in vitro method to predict the development of pulmonary fibrosis in humans following exposure to multi-walled carbon nanotubes (MWCNTs). Aerosol generators, for dry or liquid particle suspension aerosolization, and exposure chambers, including both commercially available systems and those developed by independent researchers, were evaluated. Additionally, characterization methods that can be used and the time points at which characterization can be conducted in order to interpret in vitro exposure results were assessed. Summarized below is the information presented and discussed regarding the relevance of various aerosol generation and characterization techniques specific to aerosolized MWCNTs exposed to cells cultured at the air-liquid interface (ALI). The generation of MWCNT aerosols relevant to human exposures and their characterization throughout exposure in an ALI system is critical for extrapolation of in vitro results to toxicological outcomes in humans.

  7. Use of the comet assay to measure DNA damage in cells exposed to photosensitizers and gamma radiation

    Science.gov (United States)

    Pouget, J.-P.; Ravanat, J.-L.; Douki, T.; Richard, M.-J.; Cadet, J.

    1999-01-01

    We used the comet assay associated with DNA-glycosylases to estimate DNA damage in cells exposed to gamma irradiation or photosensitized either with methylene blue or orange acridine. A calibration performed using irradiation allowed the measurement of the steady-state level and the yield of 8-oxodGuo as well as strand breaks and alkali-labile sites. Nous avons utilisé la méthode des comètes associée à des ADN-glycosylases, pour estimer les dommages de l'ADN dans des cellules après l'exposition à un rayonnement gamma ou après photosensibilisation par le bleu de méthylène ou l'acridine orange. Une calibration de la méthode des comètes a permis de mesurer le niveau basal et les taux de formation de 8-oxodGuo ainsi que le nombre de cassures de brins et de sites alcali labiles.

  8. Increased oxidative stress and toxicity in ADH and CYP2E1 overexpressing human hepatoma VL-17A cells exposed to high glucose.

    Science.gov (United States)

    Chandrasekaran, Karthikeyan; Swaminathan, Kavitha; Kumar, S Mathan; Clemens, Dahn L; Dey, Aparajita

    2012-05-01

    High glucose mediated oxidative stress and cell death is a well documented phenomenon. Using VL-17A cells which are HepG2 cells over-expressing alcohol dehydrogenase (ADH) and cytochrome P450 2E1 (CYP2E1) and control HepG2 cells, the association of ADH and CYP2E1 with high glucose mediated oxidative stress and toxicity in liver cells was investigated. Cell viability was measured and apoptosis or necrosis was determined through caspase-3 activity, Annexin V-propidium iodide staining and detecting decreases in mitochondrial membrane potential. Reactive oxygen species, lipid peroxidation and the formation of advanced glycated-end products were assessed. The levels of several antioxidants which included glutathione, glutathione peroxidase, catalase and superoxide dismutase were altered in high glucose treated VL-17A cells. Greater toxicity was observed in VL-17A cells exposed to high glucose when compared to HepG2 cells. Oxidative stress parameters were greatly increased in high glucose exposed VL-17A cells and apoptotic cell death was observed. Inhibition of CYP2E1 or caspase 3 or addition of the antioxidant trolox led to significant decreases in high glucose mediated oxidative stress and toxicity. Thus, the over-expression of ADH and CYP2E1 in liver cells is associated with increased high glucose mediated oxidative stress and toxicity.

  9. Identification of cell surface-exposed proteins involved in the fimbria-mediated adherence of enteroaggregative Escherichia coli to intestinal cells.

    Science.gov (United States)

    Izquierdo, Mariana; Navarro-Garcia, Fernando; Nava-Acosta, Raul; Nataro, James P; Ruiz-Perez, Fernando; Farfan, Mauricio J

    2014-04-01

    Fimbria-mediated adherence to the intestinal epithelia is a key step in enteroaggregative Escherichia coli (EAEC) pathogenesis. To date, four fimbriae have been described for EAEC; aggregative adherence fimbria II (AAF/II) is the most important adherence factor for EAEC prototype strain 042. Previously, we described results showing that extracellular matrix (ECM) components might be involved in the recognition of AAF/II fimbriae by intestinal cells. In this study, we sought to identify novel potential receptors on intestinal epithelial cells recognized by the AAF/II fimbriae. Purified AafA-dsc protein, the major subunit of AAF/II fimbriae, was incubated with a monolayer of T84 cells, cross-linked to the surface-exposed T84 cell proteins, and immunoprecipitated by using anti-AafA antibodies. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of cellular proteins bound to AafA-dsc protein identified laminin (previously recognized as a potential receptor for AAF/II) and cytokeratin 8 (CK8). Involvement of the major subunit of AAF/II fimbriae (AafA protein) in the binding to recombinant CK8 was confirmed by adherence assays with purified AAF/II fimbriae, AafA-dsc protein, and strain 042. Moreover, HEp-2 cells transfected with CK8 small interfering RNA (siRNA) showed reduced 042 adherence compared with cells transfected with scrambled siRNA as a control. Adherence of 042 to HEp-2 cells preincubated with antibodies against ECM proteins or CK8 was substantially reduced. Altogether, our results supported the idea of a role of CK8 as a potential receptor for EAEC.

  10. Decrease of reactive oxygen species-related biomarkers in the tissue-mimic 3D spheroid culture of human lung cells exposed to zinc oxide nanoparticles.

    Science.gov (United States)

    Kim, Eunjoo; Jeon, Won Bae; Kim, Soonhyun; Lee, Soo-Keun

    2014-05-01

    Common 2-dimensional (2D) cell cultures do not adequately represent cell-cell and cell-matrix signaling and substantially different diffusion/transport pathways. To obtain tissue-mimic information on nanoparticle toxicity from in vitro cell tests, we used a 3-dimensional (3D) culture of human lung cells (A549) prepared with elastin-like peptides modified with an arginine-glycine-aspartate motif. The 3D cells showed different cellular phenotypes, gene expression profiles, and functionalities compared to the 2D cultured cells. In gene array analysis, 3D cells displayed the induced extracellular matrix (ECM)-related biological functions such as cell-to-cell signaling and interaction, cellular function and maintenance, connective tissue development and function, molecular transport, and tissue morphology. Additionally, the expression of ECM-related molecules, such as laminin, fibronectin, and insulin-like growth factor binding protein 3 (IGFBP3), was simultaneously induced at both mRNA and protein levels. When 0.08-50 microg/ml zinc oxide nanoparticles (ZnO-NPs) were administered to 2D and 3D cells, the cell proliferation was not significantly changed. The level of molecular markers for oxidative stress, such as superoxide dismutase (SOD), Bcl-2, ATP synthase, and Complex IV (cytochrome C oxidase), was significantly reduced in 2D culture when exposed to 10 microg/ml ZnO-NPs, but no significant decrease was detected in 3D culture when exposed to the same concentration of ZnO-NPs. In conclusion, the tissue-mimic phenotype and functionality of 3D cells could be achieved through the elevated expression of ECM components. The 3D cells were expected to help to better predict the nanotoxicity of ZnO-NPs at tissue-level by increased cell-cell and cell-ECM adhesion and signaling. The tissue-mimic morphology would also be useful to simulate the diffusion/transport of the nanoparticles in vitro.

  11. Alveolar epithelial cells (A549) exposed at the air-liquid interface to diesel exhaust: First study in TNO's powertrain test center

    NARCIS (Netherlands)

    Kooter, I.M.; Alblas, M.J.; Jedynska, A.D.; Steenhof, M.; Houtzager, M.M.G.; Ras, M.G. van

    2013-01-01

    Air–liquid interface (ALI) exposures enable in vitro testing ofmixtures of gases and particles such as diesel exhaust (DE). The main objective of this study was to investigate the feasibility of exposing human lung epithelial cells at the ALI to complete DE generated by a heavy-duty truck in the sta

  12. Genetic damage in mammalian somatic cells exposed to radiofrequency radiation: a meta-analysis of data from 63 publications (1990-2005).

    Science.gov (United States)

    VIjayalaxmi; Prihoda, Thomas J

    2008-05-01

    During the last several decades, numerous researchers have examined the potential of in vitro and /or in vivo exposure of radiofrequency( RF) radiation to damage the genetic material in mammalian somatic cells. A meta-analysis of reported data was conducted to obtain a quantitative estimate ( with 95% confidence intervals) of genotoxicity in RF-radiation-exposed cells compared with sham-exposed/unexposed control cells. The extent of genotoxicity was assessed for various end points, including single- and double-strand breaks in the DNA, incidence of chromosomal aberrations, micronuclei and sister chromatid exchanges. Among the several variables in the experimental protocols used in individual investigations, the influence of three specific variables related to RF-radiation exposure characteristics was examined in the meta-analysis: frequency, specific absorption rate, and exposure as continuous-wave, pulsed-wave and occupationally exposed/cell phone users. The overall data indicated that (1) the difference between RF-radiation exposure was small with few exceptions; (2) at certain RF radiation exposure conditions, there were statistically significant increases in genotoxicity for some end points; and (3) the mean indices for chromosomal aberrations and micronuclei in RF-radiation -exposed and sham-/unexposed controls were within the spontaneous levels reported in the historical database. Considerable evidence for publication bias was found in the meta-analysis.

  13. Suppression of antigen-specific antibody responses in mice exposed to perfluorooctanoic acid: Role of PPARalpha and T- and B-cell targeting

    Science.gov (United States)

    T-cell-dependent antibody responses (TDAR) are suppressed in female C57BL/6N mice exposed to ≥3.75 mg/kg of perfluorooctanoic acid (PFOA) for 15 days. To determine if suppression of humoral immunity by PFOA is peroxisome proliferator activated receptor alpha (PPARa)-dependent and...

  14. MATRIX METALLOPROTEINS (MMP)-MEDIATED PHOSPHORYLATION OF THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) IN HUMAN AIRWAY EPITHELIAL CELLS (HAEC) EXPOSED TO ZINC (ZN)

    Science.gov (United States)

    Matrix Metalloproteinase (MMP)-Mediated Phosphorylation of The Epidermal Growth Factor Receptor (EGFR) in Human Airway Epithelial Cells (HAEC) Exposed to Zinc (Zn)Weidong Wu, James M. Samet, Robert Silbajoris, Lisa A. Dailey, Lee M. Graves, and Philip A. BrombergCenter fo...

  15. Metabolomic effects in HepG2 cells exposed to four TiO2 amd two CeO2 naomaterials

    Science.gov (United States)

    Abstract It is difficult to evaluate nanomaterials potential toxicity and to make science-based societal choices. To better assess potential hepatotoxicity issues, human liver HepG2 cells were exposed to four Ti02 and two Ce02 nanomaterials at 30 ug m1-1 for t...

  16. Differential responses of healthy and chronic obstructive pulmonary diseased human bronchial epithelial cells repeatedly exposed to air pollution-derived PM4.

    Science.gov (United States)

    Leclercq, B; Happillon, M; Antherieu, S; Hardy, E M; Alleman, L Y; Grova, N; Perdrix, E; Appenzeller, B M; Lo Guidice, J-M; Coddeville, P; Garçon, G

    2016-11-01

    While the knowledge of the underlying mechanisms by which air pollution-derived particulate matter (PM) exerts its harmful health effects is still incomplete, detailed in vitro studies are highly needed. With the aim of getting closer to the human in vivo conditions and better integrating a number of factors related to pre-existing chronic pulmonary inflammatory, we sought to develop primary cultures of normal human bronchial epithelial (NHBE) cells and chronic obstructive pulmonary disease (COPD)-diseased human bronchial epithelial (DHBE) cells, grown at the air-liquid interface. Pan-cytokeratin and MUC5AC immunostaining confirmed the specific cell-types of both these healthy and diseased cell models and showed they are closed to human bronchial epithelia. Thereafter, healthy and diseased cells were repeatedly exposed to air pollution-derived PM4 at the non-cytotoxic concentration of 5 μg/cm(2). The differences between the oxidative and inflammatory states in non-exposed NHBE and COPD-DHBE cells indicated that diseased cells conserved their specific physiopathological characteristics. Increases in both oxidative damage and cytokine secretion were reported in repeatedly exposed NHBE cells and particularly in COPD-DHBE cells. Diseased cells repeatedly exposed had lower capacities to metabolize the organic chemicals-coated onto the air-pollution-derived PM4, such as benzo[a]pyrene (B[a]P), but showed higher sensibility to the formation of OH-B[a]P DNA adducts, because their diseased state possibly affected their defenses. Differential profiles of epigenetic hallmarks (i.e., global DNA hypomethylation, P16 promoter hypermethylation, telomere length shortening, telomerase activation, and histone H3 modifications) occurred in repeatedly exposed NHBE and particularly in COPD-DHBE cells. Taken together, these results closely supported the highest responsiveness of COPD-DHBE cells to a repeated exposure to air pollution-derived PM4. The use of these innovative in

  17. Superantigen-primed T cells exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) replicate poorly following recall encounter

    Energy Technology Data Exchange (ETDEWEB)

    Faulconer, Laura; Camacho, Iris; Nagarkatti, Mitzi [Virginia Commonwealth University, Department of Microbiology and Immunology, Medical College of Virginia Campus, 980613, Richmond, VA (United States); Nagarkatti, Prakash S. [Virginia Commonwealth University, Department of Pharmacology and Toxicology, Medical College of Virginia Campus, 980613, Richmond, VA (United States)

    2006-03-15

    The current study investigated the effect of tetrachlorodibenzo-p-dioxin (TCDD) on the ability of staphylococcal enterotoxin A (SEA)-primed T cells to divide by dual-labeling the cells with 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) and antibodies against the specific T cell receptors. C57BL/6 wild-type mice were injected ip with TCDD (10 {mu}g/kg body weight) followed by hind footpad injections of SEA (10 {mu}g/footpad). The draining popliteal lymph nodes (PLN) were harvested 1-4 days posttreatment, labeled with CFSE and cultured for 1-4 days without further stimulation or in the presence of the recall antigen. TCDD-exposed SEA-reactive V{beta}3+ and V{beta}11+ T cells showed decreased cell divisions upon in vitro culture in the absence of any stimulation, which correlated with increased levels of apoptosis. The recall cell-division response was also defective in SEA-reactive T cells isolated from TCDD-exposed mice. However, during the recall response, cells from TCDD-exposed mice did not exhibit a defect in apoptosis, suggesting the defective recall response may result from a state of anergy rather than increased apoptosis. Using AhR knockout (KO) mice, we found AhR involvement in the regulation of defective cell division and apoptosis induced by TCDD. Together, these data demonstrate, while TCDD-induced apoptosis may account for the decreased primary T cell proliferative response, that the reduced cell division seen during subsequent exposure to recall antigen may result from a state of anergy. The study also demonstrates that a combined use of superantigen and CFSE may offer a simple and useful tool to monitor the ability of immunotoxicants to alter the proliferative responsiveness of antigen-specific T cells. (orig.)

  18. Analysis of Chromosomal Aberrations after Low and High Dose Rate Gamma Irradiation in ATM or NBS Suppressed Human Fibroblast Cells

    Science.gov (United States)

    Hada, M.; Huff, J. L.; Patel, Z.; Pluth, J. M.; George, K. A.; Cucinotta, F. A.

    2009-01-01

    A detailed understanding of the biological effects of heavy nuclei is needed for space radiation protection and for cancer therapy. High-LET radiation produces more complex DNA lesions that may be non-repairable or that may require additional processing steps compared to endogenous DSBs, increasing the possibility of misrepair. Interplay between radiation sensitivity, dose, and radiation quality has not been studied extensively. Previously we studied chromosome aberrations induced by low- and high- LET radiation in several cell lines deficient in ATM (ataxia telangactasia mutated; product of the gene that is mutated in ataxia telangiectasia patients) or NBS (nibrin; product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase (DNA-PK) activity. We found that the yields of both simple and complex chromosomal aberrations were significantly increased in the DSB repair defective cells compared to normal cells. The increased aberrations observed for the ATM and NBS defective lines was due to a significantly larger quadratic dose-response term compared to normal fibroblasts for both simple and complex aberrations, while the linear dose-response term was significantly higher in NBS cells only for simple exchanges. These results point to the importance of the functions of ATM and NBS in chromatin modifications that function to facilitate correct DSB repair and minimize aberration formation. To further understand the sensitivity differences that were observed in ATM and NBS deficient cells, in this study, chromosomal aberration analysis was performed in normal lung fibroblast cells treated with KU-55933, a specific ATM kinase inhibitor, or Mirin, an MRN complex inhibitor involved in activation of ATM. We are also testing siRNA knockdown of these proteins. Normal and ATM or NBS suppressed cells were irradiated with gamma-rays and chromosomes were collected with a premature chromosome

  19. miR-181a and miR-630 regulate cisplatin-induced cancer cell death.

    Science.gov (United States)

    Galluzzi, Lorenzo; Morselli, Eugenia; Vitale, Ilio; Kepp, Oliver; Senovilla, Laura; Criollo, Alfredo; Servant, Nicolas; Paccard, Caroline; Hupé, Philippe; Robert, Thomas; Ripoche, Hugues; Lazar, Vladimir; Harel-Bellan, Annick; Dessen, Philippe; Barillot, Emmanuel; Kroemer, Guido

    2010-03-01

    MicroRNAs (miRNA) are noncoding RNAs that regulate multiple cellular processes, including proliferation and apoptosis. We used microarray technology to identify miRNAs that were upregulated by non-small cell lung cancer (NSCLC) A549 cells in response to cisplatin (CDDP). The corresponding synthetic miRNA precursors (pre-miRNAs) per se were not lethal when transfected into A549 cells yet affected cell death induction by CDDP, C2-ceramide, cadmium, etoposide, and mitoxantrone in an inducer-specific fashion. Whereas synthetic miRNA inhibitors (anti-miRNAs) targeting miR-181a and miR-630 failed to modulate the response of A549 to CDDP, pre-miR-181a and pre-miR-630 enhanced and reduced CDDP-triggered cell death, respectively. Pre-miR-181a and pre-miR-630 consistently modulated mitochondrial/postmitochondrial steps of the intrinsic pathway of apoptosis, including Bax oligomerization, mitochondrial transmembrane potential dissipation, and the proteolytic maturation of caspase-9 and caspase-3. In addition, pre-miR-630 blocked early manifestations of the DNA damage response, including the phosphorylation of the ataxia-telangiectasia mutated (ATM) kinase and of two ATM substrates, histone H2AX and p53. Pharmacologic and genetic inhibition of p53 corroborated the hypothesis that pre-miR-630 (but not pre-miR-181a) blocks the upstream signaling pathways that are ignited by DNA damage and converge on p53 activation. Pre-miR-630 arrested A549 cells in the G0-G1 phase of the cell cycle, correlating with increased levels of the cell cycle inhibitor p27(Kip1) as well as with reduced proliferation rates and resulting in greatly diminished sensitivity of A549 cells to the late S-G2-M cell cycle arrest mediated by CDDP. Altogether, these results identify miR-181a and miR-630 as novel modulators of the CDDP response in NSCLC.

  20. Break Point Distribution on Chromosome 3 of Human Epithelial Cells exposed to Gamma Rays, Neutrons and Fe Ions

    Science.gov (United States)

    Hada, M.; Saganti, P. B.; Gersey, B.; Wilkins, R.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    Most of the reported studies of break point distribution on the damaged chromosomes from radiation exposure were carried out with the G-banding technique or determined based on the relative length of the broken chromosomal fragments. However, these techniques lack the accuracy in comparison with the later developed multicolor banding in situ hybridization (mBAND) technique that is generally used for analysis of intrachromosomal aberrations such as inversions. Using mBAND, we studied chromosome aberrations in human epithelial cells exposed in vitro to both low or high dose rate gamma rays in Houston, low dose rate secondary neutrons at Los Alamos National Laboratory and high dose rate 600 MeV/u Fe ions at NASA Space Radiation Laboratory. Detailed analysis of the inversion type revealed that all of the three radiation types induced a low incidence of simple inversions. Half of the inversions observed after neutron or Fe ion exposure, and the majority of inversions in gamma-irradiated samples were accompanied by other types of intrachromosomal aberrations. In addition, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosome exchanges. We further compared the distribution of break point on chromosome 3 for the three radiation types. The break points were found to be randomly distributed on chromosome 3 after neutrons or Fe ions exposure, whereas non-random distribution with clustering break points was observed for gamma-rays. The break point distribution may serve as a potential fingerprint of high-LET radiation exposure.

  1. Effect of sodium on photovoltaic properties of dye-sensitized solar cells assembled with anatase TiO2 nanosheets with exposed {001} facets.

    Science.gov (United States)

    Wu, Xia; Lu, Gaoqing Max; Wang, Lianzhou

    2013-02-01

    Anatase TiO(2) nanosheets with exposed reactive {001} facets were prepared in the presence of HF. The photovoltaic properties of NaOH-washed anatase TiO(2) nanosheets with exposed {001} facets were investigated by assembling the TiO(2) as photoanodes in dye-sensitized solar cells (DSSCs). A decreased overall efficiency and increased recombination rate was observed in comparison with the H(2)O-washed counterpart by both dark current scan and open-circuit voltage decay scan, and XPS confirmed that the deleterious effect of sodium ions is responsible for this reduced efficiency in DSSCs.

  2. Level of reactive oxygen species induced by p21Waf1/CIP1 is critical for the determination of cell fate.

    Science.gov (United States)

    Inoue, Takafumi; Kato, Kiyoko; Kato, Hidenori; Asanoma, Kazuo; Kuboyama, Ayumi; Ueoka, Yousuke; Yamaguchi, Shin-ichiro; Ohgami, Tatsuhiro; Wake, Norio

    2009-07-01

    p21(WAF(1)/)(CIP(1)) is a well-known cell cycle regulatory protein which is overexpressed in several cancer cell lines, and known to determine cell fate. We generated three recombinant adenovirus vectors that expressed either the full-length p21 (Ad-p21F), a p21 mutant with a deletion of the C-terminal proliferative cell nuclear antigen (PCNA) binding domain (Ad-p21N), or a p21 mutant with a deletion of the N-terminal cyclin-dependent kinase binding domain (Ad-p21C). We transfected these vectors into five cancer cell lines. Premature senescence was induced in all of the lines only following transfection with Ad-p21N and Ad-p21F. In addition, apoptosis was also induced in LoVo and HCT116 cells that harbored wild-type p53 and the reactive oxygen species (ROS) level was higher than in senescent cells. Finally, the induction of apoptosis was inhibited by using siRNA to downregulate p53. This observation implies that there is a feedback signaling loop involving p21/ROS/p53 in apoptotic responses. It appears to be, at least in part, driven by high levels of p21 protein. Next, we investigated the cell death effect of endogenous p21 protein on cell fate using sodium butyrate (NaB). Treatment with 1 mM NaB or 2 to 5 mM NaB induced senescence or apoptosis, respectively. The level of intracellular ROS in 5 mM NaB treated cells was 2-fold higher, compared with that in 1 mM NaB treated cells. We also demonstrated that DNA damage response signals including ataxia telangiectasia mutated, gammaH2AX, and p38 MAPK were involved in NaB-induced cell death. The magnitude of intracellular ROS levels in response to p21 elicited either senescence or apoptosis in the cancer cell lines.

  3. Chromosome-wide aneuploidy study of cultured circulating myeloid progenitor cells from workers occupationally exposed to formaldehyde

    NARCIS (Netherlands)

    Lan, Qing; Smith, Martyn T; Tang, Xiaojiang; Guo, Weihong; Vermeulen, Roel; Ji, Zhiying; Hu, Wei; Hubbard, Alan E; Shen, Min; McHale, Cliona M; Qiu, Chuangyi; Liu, Songwang; Reiss, Boris; Beane-Freeman, Laura; Blair, Aaron; Ge, Yichen; Xiong, Jun; Li, Laiyu; Rappaport, Stephen M; Huang, Hanlin; Rothman, Nathaniel; Zhang, Luoping

    2015-01-01

    Formaldehyde (FA) is an economically important industrial chemical to which millions of people worldwide are exposed environmentally and occupationally. Recently, the International Agency for Cancer Research concluded that there is sufficient evidence that FA causes leukemia, particularly myeloid le

  4. Hypersensitivity to ionizing radiation, in vitro, in a new chromosomal breakage disorder, the Nijmegen Breakage Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Taalman, R.D.F.M.; Scheres, J.M.J.C.; Hustinx, T.W.J. (Katholieke Univ. Nijmegen (Netherlands). Dept. of Human Genetics); Jaspers, N.G.J.; de Wit, J. (Erasmus Universiteit, Rotterdam (Netherlands). Lab. of Cell Biology and Genetics)

    1983-02-01

    The Nijmegen Breakage Syndrome (NBS) is a new chromosomal instability disorder different from ataxia telangiectasia (AT) and other chromosome-breakage syndromes. Cells from an NBS patient appeared hypersensitive to X-irradiation. X-rays induced significantly more chromosomal damage in NBS lymphocytes and fibroblasts than in normal cells. The difference was most pronounced after irradiation in G/sub 2/. Further, NBS fibroblasts were more readily by X-rays than normal fibroblasts. In addition, the DNA synthesis in NBS cells was more resistant to X-rays and bleomycin than that in normal cells. The reaction of NBS cells to X-rays and bleomycin was similar to that of cells from patients with ataxia telangiectasia. Our results indicate that NBS and AT, which also have similar chromosomal characteristics, must be closely related.

  5. Mechanical stretch exacerbates the cell death in SH-SY5Y cells exposed to paraquat: mitochondrial dysfunction and oxidative stress.

    Science.gov (United States)

    Wang, Fang; Franco, Rodrigo; Skotak, Maciej; Hu, Gang; Chandra, Namas

    2014-03-01

    Recent studies suggest that traumatic brain injury (TBI) and pesticide exposure increase the risk of Parkinson's disease (PD), but the molecular mechanisms involved remain unclear. Using an in vitro model of TBI, we evaluated the role of mitochondrial membrane potential (ΔΨm) and mitochondrial reactive oxygen species (ROS) induced by stretch on dopaminergic cell death upon paraquat exposure. Human dopaminergic neuroblastoma SH-SY5Y cells grown on silicone membrane were stretched at mild (25%) and moderate (50%) strain prior to paraquat exposure. We observed that moderate stretch (50% strain) increased the vulnerability of cells to paraquat demonstrated by the loss of plasma membrane integrity (propidium iodide-uptake) and decreased mitochondrial activity (MTT assay). Mitochondrial depolarization occurred immediately after stretch, while mitochondrial ROS increased rapidly and remained elevated for up to 4h after the stretch injury. Intracellular glutathione (GSH) stores were also transiently decreased immediately after moderate stretch. Cells treated with paraquat, or moderate stretch exhibited negligible mitochondrial depolarization at 48h post treatment, whereas in cells stretched prior to paraquat exposure, a significant mitochondrial depolarization occurred compared to samples exposed to either paraquat or stretch. Moderate stretch also increased mitochondrial ROS formation, as well as exacerbated intracellular GSH loss induced by paraquat. Overexpression of manganese superoxide dismutase (MnSOD) markedly diminished the deleterious effects of stretch in paraquat neurotoxicity. Our findings demonstrate that oxidative stress induced by mitochondrial dysfunction plays a critical role in the synergistic toxic effects of stretch (TBI) and pesticide exposure. Mitigation of oxidative stress via mitochondria-targeted antioxidants appears an attractive route for treatment of neurodegeneration mediated by TBI.

  6. Human adipose tissue-derived multilineage progenitor cells exposed to oxidative stress induce neurite outgrowth in PC12 cells through p38 MAPK signaling

    Directory of Open Access Journals (Sweden)

    Moriyama Mariko

    2012-08-01

    Full Text Available Abstract Background Adipose tissues contain populations of pluripotent mesenchymal stem cells that also secrete various cytokines and growth factors to support repair of damaged tissues. In this study, we examined the role of oxidative stress on human adipose-derived multilineage progenitor cells (hADMPCs in neurite outgrowth in cells of the rat pheochromocytoma cell line (PC12. Results We found that glutathione depletion in hADMPCs, caused by treatment with buthionine sulfoximine (BSO, resulted in the promotion of neurite outgrowth in PC12 cells through upregulation of bone morphogenetic protein 2 (BMP2 and fibroblast growth factor 2 (FGF2 transcription in, and secretion from, hADMPCs. Addition of N-acetylcysteine, a precursor of the intracellular antioxidant glutathione, suppressed the BSO-mediated upregulation of BMP2 and FGF2. Moreover, BSO treatment caused phosphorylation of p38 MAPK in hADMPCs. Inhibition of p38 MAPK was sufficient to suppress BMP2 and FGF2 expression, while this expression was significantly upregulated by overexpression of a constitutively active form of MKK6, which is an upstream molecule from p38 MAPK. Conclusions Our results clearly suggest that glutathione depletion, followed by accumulation of reactive oxygen species, stimulates the activation of p38 MAPK and subsequent expression of BMP2 and FGF2 in hADMPCs. Thus, transplantation of hADMPCs into neurodegenerative lesions such as stroke and Parkinson’s disease, in which the transplanted hADMPCs are exposed to oxidative stress, can be the basis for simple and safe therapies.

  7. Human Pluripotent Stem Cells and Derived Neuroprogenitors Display Differential Degrees of Susceptibility to BH3 Mimetics ABT-263, WEHI-539 and ABT-199.

    Directory of Open Access Journals (Sweden)

    Carolina Paola García

    Full Text Available Human embryonic stem cells (hESCs are hypersensitive to genotoxic stress and display lower survival ability relative to their differentiated progeny. Herein, we attempted to investigate the source of this difference by comparing the DNA damage responses triggered by the topoisomerase I inhibitor camptothecin, in hESCs, human induced pluripotent stem cells (hiPSCs and hESCs-derived neuroprogenitors (NP. We observed that upon camptothecin exposure pluripotent stem cells underwent apoptosis more swiftly and at a higher rate than differentiated cells. However, the cellular response encompassing ataxia-telangiectasia mutated kinase activation and p53 phosphorylation both on serine 15 as well as on serine 46 resulted very similar among the aforementioned cell types. Importantly, we observed that hESCs and hiPSCs express lower levels of the anti-apoptotic protein Bcl-2 than NP. To assess whether Bcl-2 abundance could account for this differential response we treated cells with ABT-263, WEHI-539 and ABT-199, small molecules that preferentially target the BH3-binding pocket of Bcl-xL and/or Bcl-2 and reduce their ability to sequester pro-apoptotic factors. We found that in the absence of stress stimuli, NP exhibited a higher sensitivity to ABT- 263 and WEHI-539 than hESCs and hiPSCs. Conversely, all tested cell types appeared to be highly resistant to the Bcl-2 specific inhibitor, ABT-199. However, in all cases we determined that ABT-263 or WEHI-539 treatment exacerbated camptothecin-induced apoptosis. Importantly, similar responses were observed after siRNA-mediated down-regulation of Bcl-xL or Bcl-2. Taken together, our results suggest that Bcl-xL contrary to Bcl-2 contributes to ensure cell survival and also functions as a primary suppressor of DNA double-strand brake induced apoptosis both in pluripotent and derived NP cells. The emerging knowledge of the relative dependence of pluripotent and progenitor cells on Bcl-2 and Bcl-xL activities may help

  8. Developmental propagation of V(D)J recombination-associated DNA breaks and translocations in mature B cells via dicentric chromosomes.

    Science.gov (United States)

    Hu, Jiazhi; Tepsuporn, Suprawee; Meyers, Robin M; Gostissa, Monica; Alt, Frederick W

    2014-07-15

    Mature IgM(+) B-cell lymphomas that arise in certain ataxia telangiectasia-mutated (ATM)-deficient compound mutant mice harbor translocations that fuse V(D)J recombination-initiated IgH double-strand breaks (DSBs) on chromosome 12 to sequences downstream of c-myc on chromosome 15, generating dicentric chromosomes and c-myc amplification via a breakage-fusion-bridge mechanism. As V(D)J recombination DSBs occur in developing progenitor B cells in the bone marrow, we sought to elucidate a mechanism by which such DSBs contribute to oncogenic translocations/amplifications in mature B cells. For this purpose, we applied high-throughput genome-wide translocation sequencing to study the fate of introduced c-myc DSBs in splenic IgM(+) B cells stimulated for activation-induced cytidine deaminase (AID)-dependent IgH class switch recombination (CSR). We found frequent translocations of c-myc DSBs to AID-initiated DSBs in IgH switch regions in wild-type and ATM-deficient B cells. However, c-myc also translocated frequently to newly generated DSBs within a 35-Mb region downstream of IgH in ATM-deficient, but not wild-type, CSR-activated B cells. Moreover, we found such DSBs and translocations in activated B cells that did not express AID or undergo CSR. Our findings indicate that ATM deficiency leads to formation of chromosome 12 dicentrics via recombination-activating gene-initiated IgH DSBs in progenitor B cells and that these dicentrics can be propagated developmentally into mature B cells where they generate new DSBs downstream of IgH via breakage-fusion-bridge cycles. We propose that dicentrics formed by joining V(D)J recombination-associated IgH DSBs to DSBs downstream of c-myc in ATM-deficient B lineage cells similarly contribute to c-myc amplification and mature B-cell lymphomas.

  9. Human Pluripotent Stem Cells and Derived Neuroprogenitors Display Differential Degrees of Susceptibility to BH3 Mimetics ABT-263, WEHI-539 and ABT-199

    Science.gov (United States)

    Dimopoulos, Nicolás Alexis; Fernandez Espinosa, Damián Darío; Miriuka, Santiago Gabriel; Sevlever, Gustavo Emilio; Romorini, Leonardo; Scassa, María Elida

    2016-01-01

    Human embryonic stem cells (hESCs) are hypersensitive to genotoxic stress and display lower survival ability relative to their differentiated progeny. Herein, we attempted to investigate the source of this difference by comparing the DNA damage responses triggered by the topoisomerase I inhibitor camptothecin, in hESCs, human induced pluripotent stem cells (hiPSCs) and hESCs-derived neuroprogenitors (NP). We observed that upon camptothecin exposure pluripotent stem cells underwent apoptosis more swiftly and at a higher rate than differentiated cells. However, the cellular response encompassing ataxia-telangiectasia mutated kinase activation and p53 phosphorylation both on serine 15 as well as on serine 46 resulted very similar among the aforementioned cell types. Importantly, we observed that hESCs and hiPSCs express lower levels of the anti-apoptotic protein Bcl-2 than NP. To assess whether Bcl-2 abundance could account for this differential response we treated cells with ABT-263, WEHI-539 and ABT-199, small molecules that preferentially target the BH3-binding pocket of Bcl-xL and/or Bcl-2 and reduce their ability to sequester pro-apoptotic factors. We found that in the absence of stress stimuli, NP exhibited a higher sensitivity to ABT- 263 and WEHI-539 than hESCs and hiPSCs. Conversely, all tested cell types appeared to be highly resistant to the Bcl-2 specific inhibitor, ABT-199. However, in all cases we determined that ABT-263 or WEHI-539 treatment exacerbated camptothecin-induced apoptosis. Importantly, similar responses were observed after siRNA-mediated down-regulation of Bcl-xL or Bcl-2. Taken together, our results suggest that Bcl-xL contrary to Bcl-2 contributes to ensure cell survival and also functions as a primary suppressor of DNA double-strand brake induced apoptosis both in pluripotent and derived NP cells. The emerging knowledge of the relative dependence of pluripotent and progenitor cells on Bcl-2 and Bcl-xL activities may help to predict

  10. Comparative analysis of cell killing and autosomal mutation in mouse kidney epithelium exposed to 1 GeV/nucleon iron ions in vitro or in situ.

    Science.gov (United States)

    Kronenberg, Amy; Gauny, Stacey; Kwoh, Ely; Connolly, Lanelle; Dan, Cristian; Lasarev, Michael; Turker, Mitchell S

    2009-11-01

    Astronauts receive exposures to high-energy heavy ions from galactic cosmic radiation. Although high-energy heavy ions are mutagenic and carcinogenic, their mutagenic potency in epithelial cells, where most human cancers develop, is poorly understood. Mutations are a critical component of human cancer, and mutations involving autosomal loci predominate. This study addresses the cytotoxic and mutagenic effects of 1 GeV/nucleon iron ions in mouse kidney epithelium. Mutant fractions were measured for an endogenous autosomal locus (Aprt) that detects all types of mutagenic events contributing to human cancer. Results for kidneys irradiated in situ are compared with results for kidney cells from the same strain exposed in vitro. The results demonstrate dose-dependent cell killing in vitro and for cells explanted 3-4 months postirradiation in situ, but in situ exposures were less likely to result in cell death than in vitro exposures. Prolonged incubation in situ (8-9 months) further attenuated cell killing at lower doses. Iron ions were mutagenic to cells in vitro and for irradiated kidneys. No sparing was seen for mutant frequency with a long incubation period in situ. In addition, the degree of mutation induction (relative increase over background) was similar for cells exposed in vitro or in situ. We speculate that the latent effects of iron-ion exposure contribute to the maintenance of an elevated mutation burden in an epithelial tissue.

  11. Toxicity of copper oxide nanoparticles in lung epithelial cells exposed at the air-liquid interface compared with in vivo assessment.

    Science.gov (United States)

    Jing, Xuefang; Park, Jae Hong; Peters, Thomas M; Thorne, Peter S

    2015-04-01

    The toxicity of spark-generated copper oxide nanoparticles (CuONPs) was evaluated in human bronchial epithelial cells (HBEC) and lung adenocarcinoma cells (A549 cells) using an in vitro air-liquid interface (ALI) exposure system. Dose-response results were compared to in vivo inhalation and instillation studies of CuONPs. Cells were exposed to filtered, particle-free clean air (controls) or spark-generated CuONPs. The number median diameter, geometric standard deviation and total number concentration of CuONPs were 9.2 nm, 1.48 and 2.27×10(7)particles/cm(3), respectively. Outcome measures included cell viability, cytotoxicity, oxidative stress and proinflammatory chemokine production. Exposure to clean air (2 or 4h) did not induce toxicity in HBEC or A549 cells. Compared with controls, CuONP exposures significantly reduced cell viability, increased lactate dehydrogenase (LDH) release and elevated levels of reactive oxygen species (ROS) and IL-8 in a dose-dependent manner. A549 cells were significantly more susceptible to CuONP effects than HBEC. Antioxidant treatment reduced CuONP-induced cytotoxicity. When dose was expressed per area of exposed epithelium there was good agreement of toxicity measures with murine in vivo studies. This demonstrates that in vitro ALI studies can provide meaningful data on nanotoxicity of metal oxides.

  12. Expression of adhesion molecules, monocyte interactions and oxidative stress in human endothelial cells exposed to wood smoke and diesel exhaust particulate matter

    DEFF Research Database (Denmark)

    Forchhammer, Lykke Ali; Loft, Steffen; Roursgaard, Martin

    2012-01-01

    -1 expression on HUVECs in mono-cultures. However, only the exposure to wood smoke particles was associated with increased expression of TNF and IL8 mRNA in THP-1 cells. We found no effect on the intracellular production of reactive oxygen species by the fluorescent probe DCFH-DA, whereas especially...... the wood smoke particles caused increased level of DNA strand breaks and oxidised guanines at concentrations with low cytotoxicity. In conclusion, our results indicate that the adherence of monocytes on endothelial cells in wood smoke particle exposed cultures depend on activation of both cell types....

  13. Adaptive HIV-specific B cell-derived humoral immune defenses of the intestinal mucosa in children exposed to HIV via breast-feeding.

    Directory of Open Access Journals (Sweden)

    Sandrine Moussa

    Full Text Available BACKGROUND: We evaluated whether B cell-derived immune defenses of the gastro-intestinal tract are activated to produce HIV-specific antibodies in children continuously exposed to HIV via breast-feeding. METHODS: Couples of HIV-1-infected mothers (n = 14 and their breastfed non HIV-infected (n = 8 and HIV-infected (n = 6 babies, and healthy HIV-negative mothers and breastfed babies (n = 10 as controls, were prospectively included at the Complexe Pédiatrique of Bangui, Central African Republic. Immunoglobulins (IgA, IgG and IgM and anti-gp160 antibodies from mother's milk and stools of breastfed children were quantified by ELISA. Immunoaffinity purified anti-gp160 antibodies were characterized functionally regarding their capacity to reduce attachment and/or infection of R5- and X4- tropic HIV-1 strains on human colorectal epithelial HT29 cells line or monocyte-derived-macrophages (MDM. RESULTS: The levels of total IgA and IgG were increased in milk of HIV-infected mothers and stools of HIV-exposed children, indicating the activation of B cell-derived mucosal immunity. Breast milk samples as well as stool samples from HIV-negative and HIV-infected babies exposed to HIV by breast-feeding, contained high levels of HIV-specific antibodies, mainly IgG antibodies, less frequently IgA antibodies, and rarely IgM antibodies. Relative ratios of excretion by reference to lactoferrin calculated for HIV-specific IgA, IgG and IgM in stools of HIV-exposed children were largely superior to 1, indicating active production of HIV-specific antibodies by the intestinal mucosa. Antibodies to gp160 purified from pooled stools of HIV-exposed breastfed children inhibited the attachment of HIV-1NDK on HT29 cells by 63% and on MDM by 77%, and the attachment of HIV-1JRCSF on MDM by 40%; and the infection of MDM by HIV-1JRCSF by 93%. CONCLUSIONS: The intestinal mucosa of children exposed to HIV by breast-feeding produces HIV-specific antibodies harbouring

  14. Oxidative stress regulated heme-oxygenase-1 and glutathione S-transferase-m1 gene expression changes in cell lines exposed to melanins

    Institute of Scientific and Technical Information of China (English)

    Jie Li; Peng Zhao; Junfeng Yang; Renyun Zhang; Shen Li; Dan Liu

    2011-01-01

    To investigate the effects of oxidative stress on substantia nigra neuronal degeneration and death in patients with Parkinson's disease, we treated neuroblastoma cells (SK-N-SH) and glioma cells with Fenton's reagent, iron chelating agent, neuromelanin and dopamine melanin. We investigated the changes in expression of nine oxidative stress-related genes and proteins. The levels of mRNAs for heme-oxygenase-1 and glutathione S-transferase-m1 were significantly reduced in SK-N-SH cells exposed to oxidative stress, and increased in glial cells treated with deferoxamine. These results revealed that SK-N-SH neurons react sensitively to oxidative stress, which implies different outcomes between these two types of cells in the substantia nigra. Moreover, the influences of neuromelanin and dopamine melanin on cell function are varied, and dopamine melanin is not a good model for neuromelanin.

  15. Chromosome Aberrations in Human Epithelial Cells Exposed Los Alamos High-Energy Secondary Neutrons: M-BAND Analysis

    Science.gov (United States)

    Hada, M.; Saganti, P. B.; Gersey, B.; Wilkins, R.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays (GCR) with the atmosphere, spacecraft structure and planetary surfaces, contribute a significant fraction to the dose equivalent radiation measurement in crew members and passengers of commercial aviation travel as well as astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility's 30L beam line (4FP30L-A/ICE House) is known to generate neutrons that simulate the secondary neutron spectrum of the Earth's atmosphere at high altitude. The neutron spectrum is also similar to that measured onboard spacecrafts like the MIR and the International Space Station (ISS). To evaluate the biological damage, we exposed human epithelial cells in vitro to the LANSCE neutron beams with an entrance dose rate of 2.5 cGy/hr, and studied the induction of chromosome aberrations that were identified with multicolor-banding in situ hybridization (mBAND) technique. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of inter-chromosomal aberrations (translocation to unpainted chromosomes) and intra-chromosomal aberrations (inversions and deletions within a single painted chromosome). Compared to our previous results with gamma-rays and 600 MeV/nucleon Fe ions of high dose rate at NSRL (NASA Space Radiation Laboratory at Brookhaven National Laboratory), the neutron data from the LANSCE experiments showed significantly higher frequency of chromosome aberrations. However, detailed analysis of the inversion type revealed that all of the three radiation types in the study induced a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intrachromosomal aberrations but few inversions were accompanied by interchromosomal aberrations. In contrast, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both

  16. Effect of Exposing Low-Frequency Electric Fields on the Proliferative Capacity and Morphological Features of Olfactory Ensheathing Cells in vitro

    Institute of Scientific and Technical Information of China (English)

    WANG Meng-hang; LI Ping; FAN Yu-bo

    2014-01-01

    Olfactory ensheathing cells (OECs) transplanted into the damaged spinal cord may be considered as a valuable remedy explorations for spinal cord repair. The proliferation of transplanted olfactory ensheathing cells depends on various environmental factors and effective cues, which may include electrical fields (EFs). In this study, we investigated the proliferative capacity, morphologic alterations of olfactory ensheathing cells derived from neonate rat that occurd when exposed to two EFs of 20 Hz, 50 mV and 20 Hz, 100 mV for 6 h. For both EF treatments, the MTT results revealed that the cellular proliferation of exposed group during the last 6 h of the experiment was statistically higher than that of control group. Then, we investigated morphological structure changes in the cells stained by Coomassie brilliant blue. Compared with control group, most of cells were present at intensively proliferating appearance including the microfilaments were long and thick and the accumulated appearance of cells. It is conceivable that electrical fields as a new approach may promote the growth and proliferation of OECs and may be engineered to control the survival of transplanted OECs in injured spinal cord. Although our results have been suggesting that EFs may be non-chemical strategies for cell proliferation, the fundamental mechanisms remain to be elucidated.

  17. Inhibition of p38 MAP kinase pathway induces apoptosis and prevents Epstein Barr virus reactivation in Raji cells exposed to lytic cycle inducing compounds

    Directory of Open Access Journals (Sweden)

    Di Renzo Livia

    2009-03-01

    Full Text Available Abstract Background EBV lytic cycle activators, such as phorbol esters, anti-immunoglobulin, transforming growth factor β (TGFβ, sodium butyrate, induce apoptosis in EBV-negative but not in EBV-positive Burkitt's lymphoma (BL cells. To investigate the molecular mechanisms allowing EBV-infected cells to be protected, we examined the expression of viral and cellular antiapoptotic proteins as well as the activation of signal transduction pathways in BL-derived Raji cells exposed to lytic cycle inducing agents. Results Our data show that, following EBV activation, the latent membrane protein 1 (LMP1 and the cellular anti-apoptotic proteins MCL-1 and BCL-2 were quickly up-regulated and that Raji cells remained viable even when exposed simultaneously to P(BU2, sodium butyrate and TGFβ. We report here that inhibition of p38 pathway, during EBV activation, led to a three fold increment of apoptosis and largely prevented lytic gene expression. Conclusion These findings indicate that, during the switch from the latent to the lytic phase of EBV infection, p38 MAPK phosphorylation plays a key role both for protecting the host cells from apoptosis as well as for inducing viral reactivation. Because Raji cells are defective for late antigens expression, we hypothesize that the increment of LMP1 gene expression in the early phases of EBV lytic cycle might contribute to the survival of the EBV-positive cells.

  18. Genotoxic Evaluation of Mexican Welders Occupationally Exposed to Welding-Fumes Using the Micronucleus Test on Exfoliated Oral Mucosa Cells: A Cross-Sectional, Case-Control Study.

    Directory of Open Access Journals (Sweden)

    Ana Cecilia Jara-Ettinger

    Full Text Available An estimated 800,000 people worldwide are occupationally exposed to welding-fumes. Previous studies show that the exposure to such fumes is associated with damage to genetic material and increased cancer risk. In this study, we evaluate the genotoxic effect of welding-fumes using the Micronucleus Test on oral mucosa cells of Mexican welders.We conducted a cross-sectional, matched case-control study of n = 66 (33 exposed welders, and 33 healthy controls. Buccal mucosa smears were collected and stained with acridine orange, observed under 100x optical amplification with a fluorescence lamp, and a single-blinded observer counted the number of micronuclei and other nuclear abnormalities per 2,000 observed cells. We compared the frequencies of micronuclei and other nuclear abnormalities, and fitted generalised linear models to investigate the interactions between nuclear abnormalities and the exposure to welding-fumes, while controlling for smoking and age.Binucleated cells and condensed-chromatin cells showed statistically significant differences between cases and controls. The frequency of micronuclei and the rest of nuclear abnormalities (lobed-nuclei, pyknosis, karyolysis, and karyorrhexis did not differ significantly between the groups. After adjusting for smoking, the regression results showed that the occurrence of binucleated cells could be predicted by the exposure to welding-fumes plus the presence of tobacco consumption; for the condensed-chromatin cells, our model showed that the exposure to welding-fumes is the only reliable predictor.Our findings suggest that Mexican welders who are occupationally exposed to welding-fumes have increased counts of binucleated and condensed-chromatin cells. Nevertheless, the frequencies of micronuclei and the rest of nuclear abnormalities did not differ between cases and controls. Further studies should shed more light on this subject.

  19. Metabolomic effects in HepG2 cells exposed to CeO2, SiO2 and CuO nanomaterials.

    Science.gov (United States)

    To better assess potential hepatotoxicity of nanomaterials, human liver HepG2 cells were exposed for three days to 5 different CeO2 (either 30 or 100 ug/ml), 3 SiO2 based (30 ug/ml) or 1 CuO (3 ug/ml) nanomaterials with dry primary particle sizes ranging from 15 to 213 nm. Metab...

  20. Aldose reductase inhibition counteracts nitrosative stress and poly(ADP-ribose) polymerase activation in diabetic rat kidney and high-glucose-exposed human mesangial cells

    OpenAIRE

    Drel, Viktor R.; Pacher, Pal; Stevens, Martin J; Obrosova, Irina G.

    2006-01-01

    Both increased aldose reductase (AR) activity and oxidative/nitrosative stress have been implicated in the pathogenesis of diabetic nephropathy, but the relation between the two factors remains a subject of debate. This study evaluated the effects of AR inhibition on nitrosative stress and poly(ADP-ribose) polymerase (PARP) activation in diabetic rat kidney and high-glucose-exposed human mesangial cells. In animal experiments, control (C) and streptozotocin-diabetic (D) rats were treated with...

  1. The medicinal fungus Antrodia cinnamomea regulates DNA repair and enhances the radiosensitivity of human esophageal cancer cells

    Directory of Open Access Journals (Sweden)

    Liu YM

    2016-10-01

    Full Text Available Yu-Ming Liu,1–3,* Yu-Kuo Liu,4,* Ling-Wei Wang,1,3 Yu-Chuen Huang,5,6 Pin-I Huang,1,3 Tung-Hu Tsai,2 Yu-Jen Chen2,7 1Department of Oncology, Division of Radiation Oncology, Taipei Veterans General Hospital, 2School of Medicine, Institute of Traditional Medicine, National Yang Ming University, Taipei, 3School of Medicine, National Yang Ming University, Taipei, 4Department of Chemical and Material Engineering, Chang Gung University, Taoyuan City, 5Department of Medical Research, China Medical University Hospital, 6School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, 7Department of Radiation Oncology, MacKay Memorial Hospital, New Taipei City, Taiwan *These authors contributed equally to this work Abstract: This study investigated the adjunctive effects of Antrodia cinnamomea mycelial fermentation broth (AC-MFB, a Taiwanese medicinal fungus, in enhancing the radiosensitivity of esophageal cancer cells. Human CE81T/VGH squamous and BE3 adenocarcinoma esophageal cancer cells were used in this study. A colony formation assay showed that pretreatment with AC-MFB decreased the survival of irradiated esophageal cancer cells, with a maximum sensitizer enhancement ratio of 1.91% and 37% survival. A DNA histogram study showed that AC-MFB pretreatment enhanced cell cycle arrest at the G2/M phase, the most radiosensitive phase. An immunofluorescence assay and a Western blotting assay showed that AC-MFB delayed the abrogation of γ-H2AX, upregulated p21 expression, and attenuated the radiation-induced phosphorylation of ataxia telangiectasia-mutated kinase and checkpoint kinase 2. An in vivo validation study showed that AC-MFB treatment tended to have a synergistic effect with radiation on the tumor growth delay of CE81T/VGH cells in BALB/c mice. These data suggest that this edible fungus product could enhance the effect of radiotherapy against esophageal cancer. Keywords: mycelial, G2/M, fermentation broth

  2. Amniotic fluid stem cells rescue both in vitro and in vivo growth, innervation, and motility in nitrofen-exposed hypoplastic rat lungs through paracrine effects.

    Science.gov (United States)

    Pederiva, F; Ghionzoli, M; Pierro, A; De Coppi, P; Tovar, J A

    2013-01-01

    Lung hypoplasia can be prevented in vitro by retinoic acid (RA). Recent evidence suggests that amniotic fluid stem (AFS) cells may integrate injured lungs and influence their recovery. We tested the hypothesis that AFS cells might improve lung growth and motility by paracrine mechanisms. Pregnant rats received either nitrofen or vehicle on E9.5. In vitro E13 embryonic lungs were cultured in the presence of culture medium alone or with RA, basophils, or AFS cells. In vivo green fluorescent protein-expressing (GFP(+)) rat AFS cells were transplanted in nitrofen-exposed rats on E10.5. E13 lung explants were cultured before analysis. The surface, the number of terminal buds, and the frequency of bronchial contractions were assessed. Protein gene product 9.5 (PGP 9.5) and α-actin protein levels were measured. The lung explants transplanted with AFS cells were stained for α-actin, PGP 9.5, and TTF-1. The levels of FGF-10, VEGFα, and TGF-β1 secreted by the AFS cells in the culture medium were measured. Comparison between groups was made by ANOVA. In vitro, the surface, the number of terminal buds, and the bronchial peristalsis were increased in nitrofen+AFS cell explants in comparison with nitrofen-exposed lungs. While nitrofen+RA lungs were similar to nitrofen+AFS ones, basophils did not normalize these measurements. PGP 9.5 protein was decreased in nitrofen lungs, but after adding AFS cells, the value was similar to controls. No differences were found in the expression of α-actin. In vivo, the surface, number of terminal buds, and peristalsis were similar to control after injection of AFS cells in nitrofen-exposed rats. Colocalization with TTF-1-positive cells was found. The levels of FGF-10 and VEGFα were increased in nitrofen+AFS cell explants, while the levels of TGF-β1 were similar to controls. Lung growth, bronchial motility, and innervation were decreased in nitrofen explants and rescued by AFS cells both in vitro and in vivo, similarly to that observed

  3. ATM protects against oxidative stress induced by oxidized low-density lipoprotein

    OpenAIRE

    2011-01-01

    Chronic oxidative stress is involved in the pathogenesis of multiple inflammatory diseases, including cardiovascular disease and atherosclerosis. The rare autosomal recessive disorder Ataxia-telangiectasia (A-T) is characterized by progressive cerebellar ataxia secondary to Purkinje cell death, immunodeficiency, and increased cancer incidence. ATM, the protein mutated in A-T, plays a key role in cellular DNA-damage responses. A-T cells show poor cellular anti-oxidant defences and increased ox...

  4. Chromosomal aberrations, sister-chromatid exchanges, cells with high frequency of SCE, micronuclei and comet assay parameters in 1, 3-butadiene-exposed workers.

    Science.gov (United States)

    Srám, R J; Rössner, P; Peltonen, K; Podrazilová, K; Mracková, G; Demopoulos, N A; Stephanou, G; Vlachodimitropoulos, D; Darroudi, F; Tates, A D

    1998-11-09

    The association of occupational exposure to 1,3-butadiene (BD) and induction of cytogenetic damage in peripheral lymphocytes was studied in 19 male workers from a monomer production unit and 19 control subjects from a heat production unit. The exposure to BD was measured by passive personal monitors. The following biomarkers were used: chromosomal aberrations (CA), sister chromatid exchanges (SCE), cells with a high frequency of SCE (HFC), micronuclei, comet assay parameters like tail length (TL) and percentage of DNA in tail [T (%)] and polymorphisms of GSTM1 and GSTT1 genotypes. BD exposure with a median value of 0.53 mg/m3 (range: 0.024-23.0) significantly increased (a) the percentage of cells with chromosomal aberrations in exposed vs. control groups (3.11% vs. 2.03%, P<0.01), (b) the frequency of SCE per cell (6.96 vs. 4.87, P<0.001), and (c) the percentage of HFC (19.9% vs. 4.1%, P<0.001). BD exposure had no significant effects on formation of micronuclei and on comet assay parameters. Effect of smoking was observed only for HFC in BD-exposed group. GSTM1 genotype affected chromosomal aberrations in exposed group, while GSTT1 genotype affected chromosomal aberrations in controls. No effect of GSTM1 or GSTT1 genotypes was observed on any other biomarkers used.

  5. Cytotoxicity, oxidative stress and expression of adhesion molecules in human umbilical vein endothelial cells exposed to dust from paints with or without nanoparticles

    DEFF Research Database (Denmark)

    Mikkelsen, Lone; Jensen, Keld A; Koponen, Ismo K;

    2013-01-01

    Abstract Nanoparticles in primary form and nanoproducts might elicit different toxicological responses. We compared paint-related nanoparticles with respect to effects on endothelial oxidative stress, cytotoxicity and cell adhesion molecule expression. Primary human umbilical vein endothelial cells...... were exposed to primary nanoparticles (fine, photocatalytic or nanosized TiO(2), aluminium silicate, carbon black, nano-silicasol or axilate) and dust from sanding reference- or nanoparticle-containing paints. Most of the samples increased cell surface expressions of vascular cell adhesion molecule-1....... In conclusion, sanding dust from nanoparticle-containing paint did not generate more oxidative stress or expression of cell adhesion molecules than sanding dust from paint without nanoparticles, whereas the primary particles had the largest effect on mass basis....

  6. Studying the protein expression in human B lymphoblastoid cells exposed to 1.8-GHz (GSM) radiofrequency radiation (RFR) with protein microarray.

    Science.gov (United States)

    Zhijian, Chen; Xiaoxue, Li; Wei, Zheng; Yezhen, Lu; Jianlin, Lou; Deqiang, Lu; Shijie, Chen; Lifen, Jin; Jiliang, He

    2013-03-29

    In the present study, the protein microarray was used to investigate the protein expression in human B-cell lymphoblastoid cells intermittently exposed to 1.8-GHz GSM radiofrequency radiation (RFR) at the specific absorption rate (SAR) of 2.0 W/kg for 24 h. The differential expression of 27 proteins was found, which were related to DNA damage repair, apoptosis, oncogenesis, cell cycle and proliferation (ratio >1.5-fold, P<0.05). The results validated with Western blot assay indicated that the expression of RPA32 was significantly down-regulated (P<0.05) while the expression of p73 was significantly up-regulated in RFR exposure group (P<0.05). Because of the crucial roles of those proteins in DNA repair and cell apoptosis, the results of present investigation may explain the biological effects of RFR on DNA damage/repair and cell apoptosis.

  7. Characterization of sub-nuclear changes in Caenorhabditis elegans embryos exposed to brief, intermediate and long-term anoxia to analyze anoxia-induced cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Trejo Jesus

    2005-12-01

    Full Text Available Abstract Background The soil nematode C. elegans survives oxygen-deprived conditions (anoxia; 2 by entering into a state of suspended animation in which cell cycle progression reversibly arrests. The majority of blastomeres of embryos exposed to anoxia arrest at interphase, prophase and metaphase. The spindle checkpoint proteins SAN-1 and MDF-2 are required for embryos to survive 24 hours of anoxia. To further investigate the mechanism of cell-cycle arrest we examined and compared sub-nuclear changes such as chromatin localization pattern, post-translational modification of histone H3, spindle microtubules, and localization of the spindle checkpoint protein SAN-1 with respect to various anoxia exposure time points. To ensure analysis of embryos exposed to anoxia and not post-anoxic recovery we fixed all embryos in an anoxia glove box chamber. Results Embryos exposed to brief periods to anoxia (30 minutes contain prophase blastomeres with chromosomes in close proximity to the nuclear membrane, condensation of interphase chromatin and metaphase blastomeres with reduced spindle microtubules density. Embryos exposed to longer periods of anoxia (1–3 days display several characteristics including interphase chromatin that is further condensed and in close proximity to the nuclear membrane, reduction in spindle structure perimeter and reduced localization of SAN-1 at the kinetochore. Additionally, we show that the spindle checkpoint protein SAN-1 is required for brief periods of anoxia-induced cell cycle arrest, thus demonstrating that this gene product is vital for early anoxia responses. In this report we suggest that the events that occur as an immediate response to brief periods of anoxia directs cell cycle arrest. Conclusion From our results we conclude that the sub-nuclear characteristics of embryos exposed to anoxia depends upon exposure time as assayed using brief (30 minutes, intermediate (6 or 12 hours or long-term (24 or 72 hours exposures

  8. Differences in T cell distribution and CCR5 expression in HIV-positive and HIV-exposed seronegative persons who inject drugs.

    Science.gov (United States)

    Kallas, Eveli; Huik, Kristi; Türk, Silver; Pauskar, Merit; Jõgeda, Ene-Ly; Šunina, Marina; Karki, Tõnis; Des Jarlais, Don; Uusküla, Anneli; Avi, Radko; Lutsar, Irja

    2016-06-01

    Some individuals remain uninfected despite repeated exposure to HIV. This protection against HIV has been partly associated with altered T cell subset distributions and CCR5 expression levels. However, the majority of studies have been conducted in sexually exposed subjects. We aimed to assess whether HIV infection and intravenous drug use were associated with differences in CCR5 expression, immune activation on the CD4+ and CD8+ T cells and T cell distribution among Caucasian persons who inject drugs (PWIDs). Analyses of the data from 41 HIV-positive PWIDs, 47 HIV-exposed seronegative PWIDs (ESNs) and 47 age- and gender-matched HIV-negative non-drug users are presented. Of all of the study subjects, 111 (82 %) were male, and the median age was 29 years. T cell phenotyping was performed in peripheral blood mononuclear cells with multicolour flow cytometry using anti-CD3, CD4, CD8, CD45RA, CD45RO, HLA-DR and CCR5 antibodies. The ESNs exhibited greater levels of immune activation and higher percentages of CD4+ CD45RA+RO+ and CD8+ CD45RA+RO+ cells compared to the controls but not the HIV-positive people. The CCR5 expression on the CD4+ T cell subsets in the ESNs was lower than that in the controls but similar to that the HIV positives. The percentages of CCR5+ T cells were similar in all study groups and in most of the studied cell populations. Intravenous drug use was similarly associated with differences in T cell subset distributions and CCR5 expression among both the HIV-positive and HIV-negative PWIDs compared with the controls.

  9. Plasma induced DNA damage: Comparison with the effects of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lazović, S.; Maletić, D.; Puač, N.; Malović, G.; Petrović, Z. Lj. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia); Leskovac, A.; Filipović, J.; Joksić, G. [Department of Physical Chemistry, Vinča Institute of Nuclear Sciences, University of Belgrade, 11001 Belgrade (Serbia)

    2014-09-22

    We use human primary fibroblasts for comparing plasma and gamma rays induced DNA damage. In both cases, DNA strand breaks occur, but of fundamentally different nature. Unlike gamma exposure, contact with plasma predominantly leads to single strand breaks and base-damages, while double strand breaks are mainly consequence of the cell repair mechanisms. Different cell signaling mechanisms are detected confirming this (ataxia telangiectasia mutated - ATM and ataxia telangiectasia and Rad3 related - ATR, respectively). The effective plasma doses can be tuned to match the typical therapeutic doses of 2 Gy. Tailoring the effective dose through plasma power and duration of the treatment enables safety precautions mainly by inducing apoptosis and consequently reduced frequency of micronuclei.

  10. PDGF-DD, a novel mediator of smooth muscle cell phenotypic modulation, is upregulated in endothelial cells exposed to atherosclerosis-prone flow patterns.

    Science.gov (United States)

    Thomas, James A; Deaton, Rebecca A; Hastings, Nicole E; Shang, Yueting; Moehle, Christopher W; Eriksson, Ulf; Topouzis, Stavros; Wamhoff, Brian R; Blackman, Brett R; Owens, Gary K

    2009-02-01

    Platelet-derived growth factor (PDGF)-BB is a well-known smooth muscle (SM) cell (SMC) phenotypic modulator that signals by binding to PDGF alphaalpha-, alphabeta-, and betabeta-membrane receptors. PDGF-DD is a recently identified PDGF family member, and its role in SMC phenotypic modulation is unknown. Here we demonstrate that PDGF-DD inhibited expression of multiple SMC genes, including SM alpha-actin and SM myosin heavy chain, and upregulated expression of the potent SMC differentiation repressor gene Kruppel-like factor-4 at the mRNA and protein levels. On the basis of the results of promoter-reporter assays, changes in SMC gene expression were mediated, at least in part, at the level of transcription. Attenuation of the SMC phenotypic modulatory activity of PDGF-DD by pharmacological inhibitors of ERK phosphorylation and by a small interfering RNA to Kruppel-like factor-4 highlight the role of these two pathways in this process. PDGF-DD failed to repress SM alpha-actin and SM myosin heavy chain in mouse SMCs lacking a functional PDGF beta-receptor. Importantly, PDGF-DD expression was increased in neointimal lesions in the aortic arch region of apolipoprotein C-deficient (ApoE(-/-)) mice. Furthermore, human endothelial cells exposed to an atherosclerosis-prone flow pattern, as in vascular regions susceptible to the development of atherosclerosis, exhibited a significant increase in PDGF-DD expression. These findings demonstrate a novel activity for PDGF-DD in SMC biology and highlight the potential contribution of this molecule to SMC phenotypic modulation in the setting of disturbed blood flow.

  11. Genetic damage in human cells exposed to non-ionizing radiofrequency fields: a meta-analysis of the data from 88 publications (1990-2011).

    Science.gov (United States)

    Vijayalaxmi; Prihoda, Thomas J

    2012-12-12

    Based on the 'limited' evidence suggesting an association between exposure to radiofrequency fields (RF) emitted from mobile phones and two types of brain cancer, glioma and acoustic neuroma, the International Agency for Research on Cancer has classified RF as 'possibly carcinogenic to humans' in group 2B. In view of this classification and the positive correlation between increased genetic damage and carcinogenesis, a meta-analysis was conducted to determine whether a significant increase in genetic damage in human cells exposed to RF provides a potential mechanism for its carcinogenic potential. The extent of genetic damage in human cells, assessed from various end-points, viz., single-/double-strand breaks in the DNA, incidence of chromosomal aberrations, micronuclei and sister chromatid exchanges, reported in a total of 88 peer-reviewed scientific publications during 1990-2011 was considered in the meta-analysis. Among the several variables in the experimental protocols used, the influence of five specific variables related to RF exposure characteristics was investigated: (i) frequency, (ii) specific absorption rate, (iii) exposure as continuous wave, pulsed wave and occupationally exposed/mobile phone users, (iv) duration of exposure, and (v) different cell types. The data indicated the following. (1) The magnitude of difference between RF-exposed and sham-/un-exposed controls was small with some exceptions. (2) In certain RF exposure conditions there was a statistically significant increase in genotoxicity assessed from some end-points: the effect was observed in studies with small sample size and was largely influenced by publication bias. Studies conducted within the generally recommended RF exposure guidelines showed a smaller effect. (3) The multiple regression analyses and heterogeneity goodness of fit data indicated that factors other than the above five variables as well as the quality of publications have contributed to the overall results. (4) More

  12. Dynamic equilibrium of endogenous selenium nanoparticles in selenite-exposed cancer cells: a deep insight into the interaction between endogenous SeNPs and proteins.

    Science.gov (United States)

    Bao, Peng; Chen, Song-Can; Xiao, Ke-Qing

    2015-12-01

    Elemental selenium (Se) was recently found to exist as endogenous nanoparticles (i.e., SeNPs) in selenite-exposed cancer cells. By sequestrating critical intracellular proteins, SeNPs appear capable of giving rise to multiple cytotoxicity mechanisms including inhibition of glycolysis, glycolysis-dependent mitochondrial dysfunction, microtubule depolymerization and inhibition of autophagy. In this work, we reveal a dynamic equilibrium of endogenous SeNP assembly and disassembly in selenite-exposed H157 cells. Endogenous SeNPs are observed both in the cytoplasm and in organelles. There is an increase in endogenous SeNPs between 24 h and 36 h, and a decrease between 36 h and 72 h according to transmission electron microscopy results and UV-Vis measurements. These observations imply that elemental Se in SeNPs could be oxidized back into selenite by scavenging superoxide radicals and ultimately re-reduced into selenide; then the assembly and disassembly of SeNPs proceed simultaneously with the sequestration and release of SeNP high-affinity proteins. There is also a possibility that the reduction of elemental Se to selenide pathway may lie in selenite-exposed cancer cells, which results in the assembly and disassembly of endogenous SeNPs. Genome-wide expression analysis results show that endogenous SeNPs significantly altered the expression of 504 genes, compared to the control. The endogenous SeNPs induced mitochondrial impairment and decreasing of the annexin A2 level can lead to inhibition of cancer cell invasion and migration. This dynamic flux of endogenous SeNPs amplifies their cytotoxic potential in cancer cells, thus provide a starting point to design more efficient intracellular self-assembling systems for overcoming multidrug resistance.

  13. Karyotypic instability and centrosome aberrations in the progeny of finite life-span human mammary epithelial cells exposed to sparsely or densely ionizing radiation.

    Science.gov (United States)

    Sudo, Hiroko; Garbe, James; Stampfer, Martha R; Barcellos-Hoff, Mary Helen; Kronenberg, Amy

    2008-07-01

    The human breast is sensitive to radiation carcinogenesis, and genomic instability occurs early in breast cancer development. This study tests the hypothesis that ionizing radiation elicits genomic instability in finite life-span human mammary epithelial cells (HMEC) and asks whether densely ionizing radiation is a more potent inducer of instability. HMEC in a non-proliferative state were exposed to X rays or 1 GeV/nucleon iron ions followed by delayed plating. Karyotypic instability and centrosome aberrations were monitored in expanded clonal isolates. Severe karyotypic instability was common in the progeny of cells that survived X-ray or iron-ion exposure. There was a lower dose threshold for severe karyotypic instability after iron-ion exposure. More than 90% of X-irradiated colonies and >60% of iron-ion-irradiated colonies showed supernumerary centrosomes at levels above the 95% upper confidence limit of the mean for unirradiated clones. A dose response was observed for centrosome aberrations for each radiation type. There was a statistically significant association between the incidence of karyotypic instability and supernumerary centrosomes for iron-ion-exposed colonies and a weaker association for X-irradiated colonies. Thus genomic instability occurs frequently in finite life-span HMEC exposed to sparsely or densely ionizing radiation and may contribute to radiation-induced breast cancer.

  14. The versatile functions of ATM kinase

    Directory of Open Access Journals (Sweden)

    Rebecca J Boohaker

    2014-02-01

    Full Text Available Ataxia-telangiectasia mutated (ATM kinase, the mutation of which causes the autosomal recessive disease ataxia-telangiectasia, plays an essential role in the maintenance of genome stability. Extensive studies have revealed that activated ATM signals to a massive list of proteins to facilitate cell cycle checkpoints, DNA repair, and many other aspects of physiological responses in the event of DNA double-strand breaks. ATM also plays functional roles beyond the well-characterized DNA damage response (DDR. In this review article, we discuss the recent findings on the molecular mechanisms of ATM in DDR, the mitotic spindle checkpoint, as well as hyperactive ATM signaling in cancer invasion and metastasis.

  15. Birth Weight and Acute Childhood Leukemia: A Meta-analysis of Observational Studies

    Science.gov (United States)

    2007-11-02

    neurofibromatosis, Shwachman syndrome, Bloom syndrome, ataxia telangiectasia, Langerhans cell histiocytosis, and Klinefelter syndrome Increased...childhood leukemia (both ALL and AML) with maternal history of fetal loss14-16 while one study reported an inverse association.17 Some studies showed...about 1.5 times).124 There is little current insight into the natural history of acute leukemia in children and the likely timing of key

  16. Clinical and Immunological Effects in Patients with Advanced Non-Small Cell Lung-Cancer after Vaccination with Dendritic Cells Exposed to an Allogeneic Tumor Cell Lysate*

    DEFF Research Database (Denmark)

    Engell-Noerregaard, Lotte; Kvistborg, Pia; Zocca, Mai-Britt

    2013-01-01

    Background: We evaluated the clinical and immunological effects of dendritic cell (DC) vaccination of patients with NSCLC. Autologous DCs were pulsed with a MAGE containing allogeneic melanoma cell lysate (MelCancerVac®, Dandrit Biotech, Copenhagen, Denmark). Imiquimod cream, proleukin......-layed effect of DC vaccination after completion of the treatment. A prospective randomized phase-IIb or -III is needed to further evaluate the use of MelCancerVac® vaccine treatment in patients with progressive NSCLC....

  17. Quantification of DNA adducts formed in liver, lungs, and isolated lung cells of rats and mice exposed to (14)C-styrene by nose-only inhalation.

    Science.gov (United States)

    Boogaard, P J; de Kloe, K P; Wong, B A; Sumner, S C; Watson, W P; van Sittert, N J

    2000-10-01

    Bronchiolo-alveolar tumors were observed in mice exposed chronically to 160 ppm styrene, whereas no tumors were seen in rats up to concentrations of 1000 ppm. Clara cells, which are predominant in the bronchiolo-alveolar region in mouse lungs but less numerous in rat and human lung, contain various cytochrome P450s, which may oxidize styrene to the rodent carcinogen styrene-7,8-oxide (SO) and other reactive metabolites. Reactive metabolites may form specific DNA adducts and induce the tumors observed in mice. To determine DNA adducts in specific tissues and cell types, rats and mice were exposed to 160 ppm [ring-U-(14)C]styrene by nose-only inhalation for 6 h in a recirculating exposure system. Liver and lungs were isolated 0 and 42 h after exposure. Fractions enriched in Type II cells and Clara cells were isolated from rat and mouse lung, respectively. DNA adduct profiles differed quantitatively and qualitatively in liver, total lung, and enriched lung cell fractions. At 0 and 42 h after exposure, the two isomeric N:7-guanine adducts of SO (measured together, HPEG) were present in liver at 3.0 +/- 0.2 and 1.9 +/- 0.3 (rat) and 1.2 +/- 0.2 and 3.2 +/- 0.5 (mouse) per 10(8) bases. Several other, unidentified adducts were present at two to three times higher concentrations in mouse, but not in rat liver. In both rat and mouse lung, HPEG was the major adduct at approximately 1 per 10(8) bases at 0 h, and these levels halved at 42 h. In both rat Type II and non-Type II cells, HPEG was the major adduct and was about three times higher in Type II cells than in total lung. For mice, DNA adduct levels in Clara cells and non-Clara cells were similar to total lung. The hepatic covalent binding index (CBI) at 0 and 42 h was 0.19 +/- 0.06 and 0.14 +/- 0.03 (rat) and 0. 25 +/- 0.11 and 0.44 +/- 0.23 (mouse), respectively. The pulmonary CBIs, based on tissues combined for 0 and 42 h, were 0.17 +/- 0.04 (rat) and 0.24 +/- 0.04 (mouse). Compared with CBIs for other genotoxicants

  18. Tailored Synthesis of Porous TiO₂ Nanocubes and Nanoparallelepipeds with Exposed {111} Facets and Mesoscopic Void Space: A Superior Candidate for Efficient Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Amoli, Vipin; Bhat, Shekha; Maurya, Abhayankar; Banerjee, Biplab; Bhaumik, Asim; Sinha, Anil Kumar

    2015-12-02

    Anatase TiO2 nanocubes and nanoparallelepipeds, with highly reactive {111} facets exposed, were developed for the first time through a modified one pot hydrothermal method, through the hydrolysis of tetrabutyltitanate in the presence of oleylamine as the morphology-controlling capping-agent and using ammonia/hydrofluoric acid for stabilizing the {111} faceted surfaces. These nanocubes/nanoparallelepipeds were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and high angle annular dark-field scanning TEM (HAADF-STEM). Accordingly, a possible growth mechanism for the nanostructures is elucidated. The morphology, surface area and the pore size distribution of the TiO2 nanostructures can be tuned simply by altering the HF and ammonia dosage in the precursor solution. More importantly, optimization of the reaction system leads to the assembly of highly crystalline, high surface area, {111} faceted anatase TiO2 nanocubes/nanoparallelepipeds to form uniform mesoscopic void space. We report the development of a novel double layered photoanode for dye sensitized solar cells (DSSCs) made of highly crystalline, self-assembled faceted TiO2 nanocrystals as upper layer and commercial titania nanoparticles paste as under layer. The bilayered DSSC made from TiO2 nanostructures with exposed {111} facets as upper layer shows a much higher power conversion efficiency (9.60%), than DSSCs fabricated with commercial (P25) titania powder (4.67%) or with anatase TiO2 nanostructures having exposed {101} facets (7.59%) as the upper layer. The improved performance in bilayered DSSC made from TiO2 nanostructures with exposed {111} facets as the upper layer is attributed to high dye adsorption and fast electron transport dynamics owing to the unique structural features of the {111} facets in TiO2. Electrochemical impedance spectroscopy (EIS) measurements conducted on the cells supported these conclusions

  19. The Omega-3 Fatty Acid Docosahexaenoic Acid Modulates Inflammatory Mediator Release in Human Alveolar Cells Exposed to Bronchoalveolar Lavage Fluid of ARDS Patients

    Directory of Open Access Journals (Sweden)

    Paolo Cotogni

    2015-01-01

    Full Text Available Background. This study investigated whether the 1 : 2 ω-3/ω-6 ratio may reduce proinflammatory response in human alveolar cells (A549 exposed to an ex vivo inflammatory stimulus (bronchoalveolar lavage fluid (BALF of acute respiratory distress syndrome (ARDS patients. Methods. We exposed A549 cells to the BALF collected from 12 ARDS patients. After 18 hours, fatty acids (FA were added as docosahexaenoic acid (DHA, ω-3 and arachidonic acid (AA, ω-6 in two ratios (1 : 2 or 1 : 7. 24 hours later, in culture supernatants were evaluated cytokines (TNF-α, IL-6, IL-8, and IL-10 and prostaglandins (PGE2 and PGE3 release. The FA percentage content in A549 membrane phospholipids, content of COX-2, level of PPARγ, and NF-κB binding activity were determined. Results. The 1 : 2 DHA/AA ratio reversed the baseline predominance of ω-6 over ω-3 in the cell membranes (P < 0.001. The proinflammatory cytokine release was reduced by the 1 : 2 ratio (P < 0.01 to <0.001 but was increased by the 1 : 7 ratio (P < 0.01. The 1 : 2 ratio reduced COX-2 and PGE2 (P < 0.001 as well as NF-κB translocation into the nucleus (P < 0.01, while it increased activation of PPARγ and IL-10 release (P < 0.001. Conclusion. This study demonstrated that shifting the FA supply from ω-6 to ω-3 decreased proinflammatory mediator release in human alveolar cells exposed to BALF of ARDS patients.

  20. HSP90 gene expression induced by aspirin is associated with damage remission in a chicken myocardial cell culture exposed to heat stress.

    Science.gov (United States)

    Zhang, X; Qian, Z; Zhu, H; Tang, S; Wu, D; Zhang, M; Kemper, N; Hartung, J; Bao, E

    2016-08-01

    To understand the potential protection of heat shock protein 90 (HSP90) induced by aspirin against heat stress damage in chicken myocardial cells, enzyme activities related to stress damage, cytopathological changes, the expression and distribution of HSP90, and HSP90 mRNA levels in the myocardial cells exposed to heat stress (42°C) for different durations with or without aspirin administration (1 mg/ml, 2 h prior) in vitro were investigated. Significant increase of enzyme levels in the supernatant of heat-stressed myocardial cells and cellular lesions characterised by acute degeneration, karyopyknosis and karyorrhexis were observed, compared to non-treated cells. However, the lesions of cells treated with aspirin were milder, characterised by earlier recovery of enzyme levels to the control levels and no obvious heat stress-related cellular necrosis. Stronger positive signals in the cytoplasm and longer retention of HSP90 signal in nuclei were observed in aspirin-treated myocardial cells than those of only heat-stressed cells. HSP90 level in the aspirin-treated myocardial cells was 11.1-fold higher than that in non-treated cells, and remained at a high level at the early stage of heat stress, whereas it was just 4.1-fold higher in only heat-stressed cells and returned rapidly to a low level. Overexpression of HSP90 mRNA in aspirin-treated cells was observed throughout the experiment, whereas HSP90 mRNA decreased significantly only in heat-stressed cells. The early higher HSP90 expression induced by aspirin during heat stress was accompanied by decreased heat stress damage, suggesting that aspirin might play an important role in preventing myocardial cells from heat stress damage in vitro.